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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

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MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT

Dear Stockholders:

          On April 20, 2017, KCG Holdings, Inc. (which we refer to as the "Company") and Virtu Financial, Inc. (which we refer to as "Virtu") entered into an Agreement and Plan of Merger (which we refer to as the "merger agreement") that provides for Virtu to acquire the Company in an all cash transaction for $20.00 per share of outstanding Company common stock. Under the merger agreement, Orchestra Merger Sub, Inc. (which we refer to as "Merger Sub"), an indirect wholly owned subsidiary of Virtu, will merge with and into the Company (which we refer to as the "merger"), so that the Company will be the surviving entity in the merger and will be an indirect wholly owned subsidiary of Virtu when the merger is completed.

          In the merger, each share of the Company's Class A common stock, par value $0.01 per share (which we refer to as the "Company common stock" and holders of which we refer to as "Company stockholders"), issued and outstanding immediately prior to the effective time of the merger (except for specified shares of Company common stock held by the Company or owned by Virtu or Merger Sub, and shares of Company common stock held by stockholders who properly exercise dissenters' rights) will be automatically converted into the right to receive $20.00 in cash without interest (which we refer to as the "merger consideration"). The merger consideration represents a premium of approximately 12.7% over $17.74, the closing price of Company common stock on The New York Stock Exchange (which we refer to as the "NYSE") on April 19, 2017, the last trading day prior to the public announcement of the merger agreement, and a premium of approximately 45.7% over $13.73, the closing price of Company common stock on the NYSE on March 14, 2017, the last trading day prior to the date on which a news organization reported publicly that Virtu had made an offer to purchase the Company. On May 31, 2017, the most recent practicable date before this proxy statement was mailed to our stockholders, the closing price for Company common stock on the NYSE was $19.86 per share. We urge you to obtain current market quotations for KCG Holdings, Inc. (trading symbol "KCG").

          As a condition and inducement to the willingness of Virtu to enter into the merger agreement, concurrently with the execution and delivery of the merger agreement, Virtu entered into a voting agreement with Jefferies LLC (which we refer to as "Jefferies"), a stockholder of the Company, which beneficially owned 15,935,031 shares of Company common stock as of the record date, representing approximately 23.4% of the outstanding Company common stock as of the record date. The voting agreement requires Jefferies, among other things, to vote all shares of Company common stock that Jefferies is entitled to vote in favor of adoption of the merger agreement and the approval of the transactions contemplated thereby, including the merger.

          The Company will hold a special meeting of its stockholders (which we refer to as the "special meeting") in connection with the merger. Company stockholders will be asked to vote to adopt the merger agreement and approve related matters, as described in the attached proxy statement. Adoption of the merger agreement requires the affirmative vote of the holders of a majority of the issued and outstanding shares of Company common stock entitled to vote on such question.

          The special meeting will be held on July 12, 2017, at 1:00 p.m., local time, at our principal executive offices, which are located at 300 Vesey Street, New York, New York 10282.

          Your vote is very important. To ensure your representation at the special meeting, please complete and return the enclosed proxy card or submit your proxy by telephone or through the Internet. Please vote promptly whether or not you expect to attend the special meeting. Submitting a proxy now will not prevent you from being able to vote in person at the special meeting.

          The board of directors of the Company has determined that the merger agreement and the merger are fair to and in the best interests of the Company and its stockholders and has unanimously approved the merger agreement and the merger and declared it advisable that the Company enter into the merger agreement. The board of directors of the Company unanimously recommends that Company stockholders vote "FOR" the adoption of the merger agreement and "FOR" the other matters to be considered at the special meeting.

          The accompanying proxy statement provides detailed information about the special meeting, the merger, the merger agreement, the documents related to the merger and other related matters. Please carefully read the entire proxy statement for discussions of the risks relating to the proposed merger. You can also obtain information about the Company from documents that the Company has filed with the Securities and Exchange Commission.

          On behalf of the board of directors of the Company, thank you for your cooperation and continued support of the Company.

		Sincerely,
Daniel Coleman Chief Executive Officer		Charles E. Haldeman, Jr. Non-Executive Chairman of the Board

          Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved the merger, passed upon the merits or fairness of the merger agreement or the transactions contemplated thereby or passed upon the adequacy or accuracy of the disclosure in this proxy statement. Any representation to the contrary is a criminal offense.

          The date of this proxy statement is June 1, 2017 and it is first being mailed or otherwise delivered to the Company's stockholders on or about June 1, 2017.

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KCG Holdings, Inc.
300 Vesey Street
New York, New York 10282

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

To be held on July 12, 2017

          NOTICE IS HEREBY GIVEN that KCG Holdings, Inc., a Delaware corporation (which we refer to as the "Company"), will hold a special meeting of holders of Class A common stock of the Company (which we refer to as "Company common stock" and holders of which we refer to as "Company stockholders") on July 12, 2017, at 1:00 p.m., local time, at our principal executive offices, which are located at 300 Vesey Street, New York, New York 10282 (which we refer to as the "special meeting") to consider and vote upon the following matters:

1.

A proposal to adopt the Agreement and Plan of Merger, dated as of April 20, 2017, by and among the Company, Virtu Financial, Inc. (which we refer to as "Virtu") and Orchestra Merger Sub, Inc. (which we refer to as "Merger Sub"), as such agreement may be amended from time to time (which we refer to as the "merger agreement"), a copy of which is attached as Annex A (which we refer to as the "merger proposal");



2.

A proposal to approve, on a non-binding, advisory basis, the compensation that certain executive officers of the Company may receive in connection with the merger pursuant to agreements or arrangements with the Company (which we refer to as the "compensation proposal"); and



3.

A proposal to approve one or more adjournments of the special meeting, if necessary or appropriate, including adjournments to permit further solicitation of proxies in favor of the merger proposal (which we refer to as the "adjournment proposal").

          The board of directors of the Company has fixed the close of business on May 24, 2017 as the record date for the special meeting. Only Company stockholders of record at that time are entitled to notice of, and to vote at, the special meeting or any adjournment or postponement thereof. Adoption of the merger proposal requires the affirmative vote of holders of a majority of the issued and outstanding shares of Company common stock entitled to vote on such question. Approval of each of the compensation proposal and the adjournment proposal requires the affirmative vote of the holders of at least a majority of the shares of Company common stock present or represented by proxy at the special meeting and entitled to vote on such question.

          The board of directors of the Company has determined that the merger agreement and the merger are fair to and in the best interests of the Company and its stockholders and has unanimously approved the merger agreement and the merger and declared it advisable that the Company enter into the merger agreement. The board of directors of the Company unanimously recommends that Company stockholders vote "FOR" the merger proposal, "FOR" the compensation proposal and "FOR" the adjournment proposal.

          Your vote is very important.    We cannot complete the merger unless Company stockholders approve the merger proposal.

          Each copy of the proxy statement mailed to Company stockholders is accompanied by a form of proxy card with instructions for voting. Regardless of whether you plan to attend the special meeting, please vote as soon as possible by accessing the Internet site listed on the proxy card, voting telephonically using the phone number listed on the proxy card or submitting your proxy card by mail. If you hold stock in your name as a stockholder of record and are voting by mail, please complete, sign, date and return the accompanying proxy card in the enclosed postage-paid return envelope. This will not prevent you from voting in person, but it will help to secure a quorum and avoid added solicitation costs. Any holder of record of Company common stock who is present at the special meeting may vote in person instead of by proxy, thereby canceling any previous proxy. In any event, a proxy may be revoked at any time before the special meeting in the manner described in the accompanying proxy statement. Information and applicable deadlines for voting through the Internet or by telephone are set forth in the enclosed proxy card instructions. If you hold your stock in "street name" through a bank, broker or other holder of record, please follow the instructions on the voting instruction card furnished by the record holder.

          Under Delaware law, Company stockholders who do not vote in favor of the adoption of the merger proposal will have the right to seek appraisal of the fair value of their shares of Company common stock as determined by the Delaware Court of Chancery if the merger is completed, but only if they submit a written demand for such an appraisal prior to the vote on the merger proposal and comply with the other procedures set forth in Section 262 of the Delaware General Corporation Law, the text of which can be found in Annex D to the accompanying proxy statement and the requirements of which section are incorporated in this notice by reference and summarized in the accompanying proxy statement. Company stockholders who do not vote in favor of the merger proposal, who submit a written demand for such an appraisal prior to the vote on the merger proposal and who comply with the other procedures set forth in Section 262 of the Delaware General Corporation Law will not receive the merger consideration.

          The enclosed proxy statement provides a detailed description of the special meeting, the merger, the merger agreement, the documents related to the merger and other related matters. We urge you to read the proxy statement, including any documents incorporated in the proxy statement by reference, and its annexes carefully and in their entirety.

		BY ORDER OF THE BOARD OF DIRECTORS
		John McCarthy General Counsel and Corporate Secretary

Date: June 1, 2017

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REFERENCES TO ADDITIONAL INFORMATION

        This proxy statement incorporates important business and financial information about the Company from documents filed with the Securities and Exchange Commission (which we refer to as the "SEC") that are not included in or delivered with this proxy statement. You can obtain any of the documents filed with or furnished to the SEC by the Company at no cost from the SEC's website at https://www.sec.gov. You may also request copies of these documents, including documents incorporated by reference into this proxy statement, at no cost by contacting the Company at the following address:

KCG Holdings, Inc.
Investor Relations
300 Vesey Street
New York, New York 10282
Telephone: (646) 682-6000

        You will not be charged for any of these documents that you request. To obtain timely delivery of these documents, you must request them no later than five business days before the date of the special meeting. This means that Company stockholders requesting documents must do so by July 5, 2017, in order to receive them before the special meeting.

        For additional questions about the merger, assistance in submitting proxies or voting shares of Company common stock or additional copies of the proxy statement or the enclosed proxy card, please contact:

Okapi Partners LLC
1212 Avenue of the Americas, 24^th Floor
New York, New York 10036
Toll Free: (855) 208-8903
Direct: (212) 297-0720
By Email: KCGHoldings@okapipartners.com

        You should rely only on the information contained in, or incorporated by reference into, this document. No one has been authorized to provide you with information that is different from that contained in, or incorporated by reference into, this document. This document is dated June 1, 2017, and you should assume that the information in this document is accurate only as of such date.

        This document does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction.

        See "Where You Can Find More Information" for more details.

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETING

        The following are some questions that you may have about the merger and the special meeting and brief answers to those questions. We urge you to read carefully the remainder of this proxy statement because the information in this section does not provide all of the information that might be important to you with respect to the merger or the special meeting. Additional important information is also contained in the documents incorporated by reference into this proxy statement. See "Where You Can Find More Information."

Q:

What is the merger?

A:

KCG Holdings, Inc. (which we refer to as the "Company"), Virtu Financial, Inc. (which we refer to as "Virtu") and Orchestra Merger Sub, Inc. (which we refer to as "Merger Sub") entered into an Agreement and Plan of Merger, dated April 20, 2017, as such agreement may be amended from time to time (which we refer to as the "merger agreement"). Under the merger agreement, Merger Sub, an indirect wholly owned subsidiary of Virtu, will merge with and into the Company (which we refer to as the "merger"), so that the Company will be the surviving entity in the merger (which we refer to as the "surviving corporation") and will be an indirect wholly owned subsidiary of Virtu when the merger is completed. A copy of the merger agreement is included in this proxy statement as Annex A.

The merger cannot be completed unless, among other things, the proposal to adopt the merger agreement is approved by the holders of a majority of the issued and outstanding shares of Class A common stock of the Company (which we refer to as "Company common stock" and holders of which we refer to as "Company stockholders") entitled to vote on such question.

Q:

Why am I receiving this proxy statement?

A:

We are delivering this document to you because it is a proxy statement being used by the board of directors of the Company (which we refer to as the "Company board") to solicit proxies of Company stockholders in connection with the adoption of the merger agreement and related matters.

The Company has called a special meeting of its stockholders (which we refer to as the "special meeting") to adopt the merger agreement and approve related matters. This document serves as the proxy statement for the special meeting and describes the proposals to be presented at the special meeting.

This proxy statement contains important information about the merger and the other proposals being voted on at the special meeting. You should read it carefully and in its entirety. The enclosed materials allow you to have your shares of Company common stock voted by proxy without attending the special meeting. Your vote is important and we encourage you to submit your proxy as soon as possible.

Q:

What are Company stockholders being asked to vote on at the special meeting?

A:

The Company is soliciting proxies from Company stockholders with respect to the following proposals:

1.

A proposal to adopt the merger agreement (which we refer to as the "merger proposal");

2.

A proposal to approve, on a non-binding, advisory basis, the compensation that certain executive officers of the Company may receive in connection with the merger pursuant to agreements or arrangements with the Company, as described in "Advisory Vote on

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Merger-Related Compensation for the Company's Named Executive Officers" (which we refer to as the "compensation proposal"); and

3.

A proposal to approve one or more adjournments of the special meeting, if necessary or appropriate, including adjournments to permit further solicitation of proxies in favor of the merger proposal (which we refer to as the "adjournment proposal").

Q:

What will Company stockholders receive in the merger?

A:

In the merger, each share of Company common stock issued and outstanding immediately prior to the effective time of the merger (which we refer to as the "effective time"), except for specified shares held by the Company or owned by Virtu or Merger Sub and shares of Company common stock held by Company stockholders who properly exercise dissenters' rights, will be converted into the right to receive $20.00 in cash without interest (which we refer to as the "merger consideration").

Q:

How will the merger affect Company equity awards?

A:

The Company equity awards will be affected as follows:

Stock Options:    At the effective time, each outstanding option to purchase shares of Company common stock (which we refer to as a "stock option") granted under the Company's Amended and Restated Equity Plan (which we refer to as the "Company stock plan") will be cancelled and will entitle the holder thereof to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to the stock option immediately prior to the effective time and (y) the excess, if any, of the merger consideration of $20.00 per share over the exercise price per share of such stock option, less applicable taxes required to be withheld with respect to such payment. Any stock option that has an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share will be cancelled at the effective time for no consideration or payment.

Stock Appreciation Rights:    At the effective time, each outstanding stock appreciation right (which we refer to as a "SAR") granted under the Company stock plan will be cancelled and will entitle the holder thereof to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to such SAR immediately prior to the effective time and (y) the excess, if any, of the merger consideration of $20.00 per share over the exercise price per share of such SAR, less applicable taxes required to be withheld with respect to such payment. Because all outstanding SARs have an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share, all SARs will be cancelled at the effective time for no consideration or payment.

Restricted Stock Units:    At the effective time, each outstanding restricted stock unit (which we refer to as an "RSU") under the Company stock plan, whether vested or unvested, will be cancelled and will entitle the holder thereof to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to such RSU immediately prior to the effective time and (y) the merger consideration of $20.00 per share, less applicable taxes required to be withheld with respect to such payment.

Q:

What will holders of Company warrants receive in the merger?

A:

In the merger, each of the Company's warrants to purchase shares of the Company common stock issued and outstanding immediately prior to the effective time of the merger will be converted into the right to receive an amount in cash equal to the product of (A) the total number of shares of Company common stock subject to such Company warrant and (B) the excess, if any, of the

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merger consideration over the then-current exercise price per share of Company common stock (without giving effect to any of the transactions contemplated by the merger agreement) previously subject to such Company warrant, less applicable taxes required to be withheld with respect to such payment.

Q:

How does the merger consideration compare to the market price of Company common stock?

A:

The merger consideration represents a premium of approximately 12.7% over $17.74, the closing price of Company common stock on The New York Stock Exchange (which we refer to as the "NYSE") on April 19, 2017, the last trading day prior to the public announcement of the merger agreement, and a premium of approximately 45.7% over $13.73, the closing price of Company common stock on the NYSE on March 14, 2017, the last trading day prior to the date on which a news organization reported publicly that Virtu had made an offer to purchase the Company. On May 31, 2017, the most recent practicable date before this proxy statement was mailed to our stockholders, the closing price for Company common stock on the NYSE was $19.86 per share. You are encouraged to obtain current market quotations for Company common stock in connection with voting your shares.

Q:

How does the Company board recommend that I vote at the special meeting?

A:

The Company board unanimously recommends that you vote "FOR" the merger proposal, "FOR" the compensation proposal and "FOR" the adjournment proposal.

Q:

Why am I being asked to consider and vote on, by non-binding, advisory vote, the compensation proposal?

A:

Securities and Exchange Commission (which we refer to as the "SEC") rules require the Company to seek a non-binding, advisory vote to approve compensation that will or may become payable by the Company to its named executive officers in connection with the merger.

Q:

When and where is the special meeting?

A:

The special meeting will be held on July 12, 2017, at 1:00 p.m., local time, at our principal executive offices, which are located at 300 Vesey Street, New York, New York 10282.

Q:

What do I need to do now?

A:

After you have carefully read this proxy statement and have decided how you wish to vote your shares of Company common stock, please vote your shares promptly so that your shares are represented and voted at the special meeting. If you hold your shares in your name as a stockholder of record, you can complete, sign, date and mail your proxy card in the enclosed postage-paid return envelope, and we request that you do this as soon as possible. Alternatively, you may vote through the Internet or by telephone. Information and applicable deadlines for voting through the Internet or by telephone are set forth in the enclosed proxy card instructions. If you hold your shares in "street name" through a bank, broker or other holder of record, you must direct the record holder of your shares how to vote in accordance with the instructions you have received from such record holder. A "street name" stockholder who wishes to vote in person at the special meeting will need to obtain a legal proxy from the institution that holds its shares.

Q:

What constitutes a quorum for the special meeting?

A:

The presence, in person or by properly executed or otherwise documented proxy, of the holders of a majority of the issued and outstanding shares of Company common stock entitled to vote at such special meeting as of the record date is necessary to constitute a quorum at the special meeting.

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The Company cannot hold the meeting unless a quorum is present. Abstentions will be counted in determining the number of shares present at the meeting solely for the purpose of determining whether a quorum is present.

We urge you to vote promptly by proxy even if you plan to attend the meeting so that we will know as soon as possible that enough shares will be present for us to hold the meeting.

Q:

What is the vote required to approve each proposal at the special meeting?

A:

Merger Proposal:

•

Standard:  Approval of the merger proposal requires the affirmative vote of the holders of a majority of the issued and outstanding shares of Company common stock entitled to vote on such question.

•

Effect of abstentions and broker non-votes:  If you fail to vote, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other holder of record with respect to the merger proposal, it will have the same effect as a vote "AGAINST" the proposal.

Compensation Proposal:

•

Standard:  Approval of the compensation proposal requires the affirmative vote of the holders of at least a majority of the issued and outstanding shares of Company common stock present or represented by proxy at the special meeting and entitled to vote on such question.

•

Effect of abstentions and broker non-votes:  If you mark "ABSTAIN" on your proxy card, it will have the same effect as a vote "AGAINST" the proposal. If you fail to submit a proxy card or vote in person at the special meeting, or fail to instruct your bank, broker or other holder of record how to vote with respect to the adjournment proposal, it will have no effect on the proposal.

Adjournment Proposal:

•

Standard:  Whether or not a quorum is present, approval of the adjournment proposal requires the affirmative vote of the holders of at least a majority of the shares of Company common stock present or represented by proxy at the special meeting and entitled to vote on such question.

•

Effect of abstentions and broker non-votes:  If you mark "ABSTAIN" on your proxy card, it will have the same effect as a vote "AGAINST" the proposal. If you fail to submit a proxy card or vote in person at the special meeting, or fail to instruct your bank, broker or other holder of record how to vote with respect to the adjournment proposal, it will have no effect on the proposal.

Q:

Why is my vote important?

A:

If you do not vote, it will be more difficult for the Company to obtain the necessary quorum to hold the special meeting. In addition, your failure to submit a proxy or vote in person, your failure to instruct your bank or broker how to vote or your abstention will have the same effect as a vote "AGAINST" the adoption of the merger agreement.

Q:

If my shares of Company common stock are held in "street name" by my bank, broker or other holder of record, will my bank, broker or other holder of record automatically vote my shares for me?

A:

No. Your bank, broker or other holder of record cannot vote your shares without instructions from you. If your shares are held in "street name" through a bank, broker or other holder of record,

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you must provide the record holder of your shares with instructions on how to vote the shares. Please follow the voting instructions provided by such record holder. You may not vote shares held in "street name" by returning a proxy card directly to the Company, or by voting in person at the special meeting, unless you provide a legal proxy, which you must obtain from the record holder of your shares. Further, banks, brokers or other holders of record who hold shares of Company common stock on behalf of their customers may not give a proxy to the Company to vote those shares with respect to any of the proposals without specific instructions from their customers, as banks, brokers and other holders of record do not have discretionary voting power on these matters. Failure to instruct your bank, broker or other holder of record how to vote will have the same effect as a vote "AGAINST" adoption of the merger agreement.

Q:

Can Company stockholders attend the special meetings and vote their shares in person?

A:

Yes. All Company stockholders, including stockholders of record and stockholders who hold their shares through banks, brokers or other holders of record, are invited to attend the special meeting. Stockholders of record of Company common stock can vote in person at the special meeting. If you are not a stockholder of record (in other words, if your shares are held for you in "street name"), you must obtain a legal proxy, executed in your favor, from the record holder of your shares to be able to vote in person at the special meeting. If you plan to attend the special meeting, you must hold your shares in your own name or have a letter from the record holder of your shares confirming your ownership. In addition, you must bring a form of personal photo identification with you in order to be admitted to the meeting. The Company reserves the right to refuse admittance to anyone without proper proof of share ownership or without proper photo identification. Whether or not you intend to be present at the special meeting, you are urged to sign, date and return your proxy card, or to vote via the Internet or by telephone, promptly. If you are then present and wish to vote your shares in person, your original proxy may be revoked by voting at the special meeting.

Q:

Can I change my vote?

A:

Yes. If you are a stockholder of record of Company common stock, you may change your vote at any time before your shares of Company common stock are voted at the special meeting by: (i) signing and returning a proxy card with a later date; (ii) attending the special meeting in person, notifying the corporate secretary, and voting by ballot at the special meeting; (iii) voting by telephone or the Internet at a later time; or (iv) delivering a written revocation letter to the Company's Corporate Secretary at 300 Vesey Street, New York, NY 10282. If you hold your shares in "street name" through a bank, broker or other holder of record, you should contact your record holder to change your vote.

Q:

Will the Company be required to submit the merger proposal to Company stockholders even if the Company board has withdrawn, modified or qualified its recommendation?

A:

Yes. Unless the merger agreement is terminated before the special meeting, the Company is required to submit the merger proposal to Company stockholders even if the Company board has withdrawn or modified its recommendation.

Q:

Is the merger expected to be taxable to U.S. holders?

A:

Yes. The exchange of shares of Company common stock for cash pursuant to the merger generally will be a taxable transaction to U.S. holders for U.S. federal income tax purposes. If you are a U.S. holder and you exchange your shares of Company common stock in the merger for cash, you will generally recognize gain or loss in an amount equal to the difference, if any, between the amount of cash received with respect to such shares and your adjusted tax basis in such shares.

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Backup withholding may also apply to the cash payments made pursuant to the merger unless the holder or other payee provides a taxpayer identification number, certifies that such number is correct and otherwise complies with the backup withholding rules. You should read "The Merger—Material U.S. Federal Income Tax Consequences of the Merger" for a more detailed discussion of the U.S. federal income tax consequences of the merger. You should also consult your tax advisor for a complete analysis of the effect of the merger on your federal, state and local and/or foreign taxes.

Q:

Are Company stockholders entitled to dissenters' rights?

A:

Yes. Company stockholders are expected to be entitled to dissenters' rights, or appraisal rights, under Section 262 of the General Corporation Law of the State of Delaware (which we refer to as the "DGCL"). For further information, see "Appraisal Rights."

Q:

If I am a Company stockholder, should I send in my stock certificate(s) now?

A:

No. If the merger proposal is approved, after the completion of the merger, you will promptly be sent a letter of transmittal describing how you may exchange your stock certificate(s) or book-entry shares of Company common stock for the merger consideration. If your shares of Company common stock are held in "street name" through a bank, broker or other holder of record, you should contact the record holder of your shares for instructions as to how to effect the surrender of your "street name" shares of Company common stock in exchange for the merger consideration. Please do NOT return your stock certificate(s) with your proxy.

Q:

What should I do if I receive more than one set of voting materials?

A:

Company stockholders may receive more than one set of voting materials, including multiple copies of this proxy statement and multiple proxy cards or voting instruction cards. For example, if you hold shares of Company common stock in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold such shares. If you are a stockholder of record of Company common stock and your shares are registered in more than one name, you will receive more than one proxy card. Please complete, sign, date and return each proxy card and voting instruction card that you receive or otherwise follow the voting instructions set forth in this proxy statement to ensure that you vote every share of Company common stock that you own.

Q:

When do you expect the merger to be completed?

A:

The Company currently expects to complete the merger in the third quarter of 2017. However, the Company cannot assure you of when or if the merger will be completed, and completion is subject to the satisfaction of various conditions that are not within the Company's control. The Company must obtain the approval of Company stockholders to adopt the merger agreement at the special meeting. The Company and Virtu must also obtain certain regulatory approvals and satisfy certain other closing conditions.

Q:

What happens if the merger is not completed?

A:

If the merger is not completed for any reason, Company stockholders will not receive any consideration for their shares of Company common stock in connection with the merger. Instead, the Company will remain an independent, public company and the Company common stock will continue to be listed and traded on the NYSE. In addition, under certain circumstances specified in the merger agreement, the Company may be required to pay a termination fee of $45 million or up to $15 million in expense reimbursements to Virtu. See "The Merger Agreement—Termination

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Fee" for a complete discussion of the circumstances under which a termination fee or reimbursement of expenses would be required to be paid.

Q:

Whom should I call with questions?

A:

If you have any questions concerning the merger or this proxy statement, would like additional copies of this proxy statement or need help voting your shares of Company common stock, please contact the Company's proxy solicitor, Okapi Partners LLC, at 1212 Avenue of the Americas, 24^th Floor, New York, New York 10036, toll-free at (855) 208-8903 or direct at (212) 297-0720, or by email at KCGHoldings@okapipartners.com.

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CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS

        This proxy statement contains certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and is intended to be protected by the safe harbor provided therein. We generally identify forward-looking statements, particularly those statements regarding the benefits of the proposed merger between Virtu and the Company, the anticipated timing of the transaction and the products and markets of each company, by terminology such as "outlook," "believes," "expects," "potential," "continues," "may," "will," "would," "could," "should," "seeks," "approximately," "predicts," "intends," "plans," "estimates," "anticipates," "projects," "strategy," "future," "opportunity," "will likely result" or the negative version of those words or other comparable words. These forward-looking statements are not historical facts, and are based on current expectations, estimates and projections about our industry, management's beliefs and certain assumptions made by management, many of which, by their nature, are inherently uncertain and beyond our control. Accordingly, you are cautioned that any such forward-looking statements are not guarantees of future performance and are subject to certain risks, uncertainties and assumptions that are difficult to predict.

        A number of important factors could cause actual results to differ materially from those indicated by the forward-looking statements in this proxy statement, including, but not limited to:

•

the merger may not be completed in a timely manner or at all, which may adversely affect the Company's business and the price of Company common stock;



•

the Company stockholders may fail to approve the merger proposal;



•

required governmental approvals may not be obtained or may not be obtained on the terms expected or on the anticipated schedule;



•

the parties to the merger agreement may fail to satisfy other conditions to the completion of the merger, or may not be able to meet expectations regarding the timing and completion of the merger;



•

the occurrence of any event, change or other circumstance that could give rise to the termination of the merger agreement and the risk that the Company may be required to pay a termination fee of $45 million to Virtu or reimburse certain expenses in the event that the merger agreement is terminated;



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the effect of the announcement or pendency of the merger on the Company's business relationships, operating results and business generally;



•

changes in circumstances between the signing of the merger agreement and the completion of the merger, which will not be reflected in the opinion obtained by the Company from its financial advisor;



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the inability of the Company to maintain relationships with customers, counterparties and key employees;



•

general economic or market conditions and the impact of changes in regulation applicable to the Company and to political instability generally;



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risks that the proposed merger disrupts current plans and operations of the Company and potential difficulties in the Company employee retention as a result of the announcement of the merger;



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risks related to diverting management's attention from the Company's ongoing business operations;



•

Virtu may fail to obtain the financing it needs to complete the merger; and

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•

the amount of the costs, fees, expenses and other charges related to the merger.

        For additional factors that could materially affect our financial results and our business generally, please refer to the Company's filings with the SEC, including but not limited to, the factors, uncertainties and risks described under the headings "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations." See "Where You Can Find More Information." Neither Virtu nor the Company undertakes any obligation to revise these statements following the date of this communication, except as required by law.

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THE SPECIAL MEETING

        This section contains information for Company stockholders about the special meeting that the Company has called to allow Company stockholders to consider and vote on the merger proposal and other matters. The Company is mailing this proxy statement to you, as a Company stockholder, on or about June 1, 2017. This proxy statement is accompanied by a notice of the special meeting and a form of proxy card that the Company board is soliciting for the Company at the special meeting and at any adjournments or postponements thereof.

Date, Time and Place of the Special Meeting

        This proxy statement is being furnished to our stockholders as part of the solicitation of proxies by the Company board from Company stockholders for use at the special meeting to be held on July 12, 2017, at 1:00 p.m., local time, at our principal executive offices, which are located at 300 Vesey Street, New York, New York 10282, or at any postponement or adjournment thereof.

Purpose of the Special Meeting

        At the special meeting, you will be asked to consider and vote upon the following matters:

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The merger proposal (Proposal 1 on your proxy card);



•

The compensation proposal (Proposal 2 on your proxy card); and



•

The adjournment proposal (Proposal 3 on your proxy card).

Recommendation of the Company Board of Directors

        The Company's board of directors has determined that the merger agreement and the merger are fair to and in the best interests of the Company and its stockholders and has unanimously approved the merger agreement and the merger and declared it advisable that the Company enter into the merger agreement. The Company board unanimously recommends that Company stockholders vote "FOR" the merger proposal, "FOR" the compensation proposal and "FOR" the adjournment proposal. See "The Merger—Reasons for the Merger; Recommendation of the Company Board of Directors" for a more detailed discussion of the Company board's recommendation.

Record Date and Quorum

        The Company board has fixed the close of business on May 24, 2017 as the record date for the determination of Company stockholders entitled to notice of, and to vote at, the special meeting. As of the close of business on the record date, there were 68,055,342 shares of Company common stock (including certain RSUs) outstanding and entitled to vote, held by approximately 142 holders of record. You will have one vote on each matter properly coming before the special meeting for each share of Company common stock that you owned on the record date.

        Holders of a majority of the shares of Company common stock issued and outstanding and entitled to vote at the special meeting, present in person or represented by proxy, will constitute a quorum for the transaction of business at the special meeting. All shares of Company common stock present in person or represented by proxy, including abstentions, will be treated as present for purposes of determining the presence or absence of a quorum for all matters voted on at the special meeting. Because, under applicable rules, banks, brokers and other holders of record holding shares in "street name" do not have discretionary voting authority with respect to any of the three proposals described in this proxy statement, if a beneficial owner of Company common stock held in "street name" does not give voting instructions to the record holder of its, his or her shares, then those shares will not be

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counted as present in person or by proxy at the special meeting if no other proposals are brought before the special meeting.

Vote Required

Merger Proposal

•

Standard:  Approval of the merger proposal requires the affirmative vote of the holders of a majority of the issued and outstanding shares of Company common stock entitled to vote on such question.



•

Effect of abstentions and broker non-votes:  If you fail to vote, mark "ABSTAIN" on your proxy or fail to instruct your bank, broker or other holder of record with respect to the merger proposal, it will have the same effect as a vote "AGAINST" the proposal.

Compensation Proposal

•

Standard:  Approval of the compensation proposal requires the affirmative vote of the holders of at least a majority of the shares of Company common stock present or represented by proxy at the special meeting and entitled to vote on such question.



•

Effect of abstentions and broker non-votes:  If you mark "ABSTAIN" on your proxy card, it will have the same effect as a vote "AGAINST" the proposal. If you fail to submit a proxy card or vote in person at the special meeting, or fail to instruct your bank, broker or other holder of record how to vote with respect to the adjournment proposal, it will have no effect on the proposal.

Adjournment Proposal

•

Standard:  Whether or not a quorum is present, approval of the adjournment proposal requires the affirmative vote of the holders of at least a majority of the shares of Company common stock present or represented by proxy at the special meeting and entitled to vote on such question.



•

Effect of abstentions and broker non-votes:  If you mark "ABSTAIN" on your proxy card, it will have the same effect as a vote "AGAINST" the proposal. If you fail to submit a proxy card or vote in person at the special meeting, or fail to instruct your bank, broker or other holder of record how to vote with respect to the adjournment proposal, it will have no effect on the proposal.

Shares Subject to Voting Agreement

        As a condition and inducement to the willingness of Virtu to enter into the merger agreement, concurrently with the execution and delivery of the merger agreement, Virtu entered into a voting agreement with Jefferies, which beneficially owned 15,935,031 shares of Company common stock as of the record date, representing approximately 23.4% of the outstanding Company common stock as of the record date. The voting agreement requires Jefferies to, among other things, vote all shares of Company common stock that Jefferies is entitled to vote in favor of adoption of the merger agreement and the approval of the transactions contemplated thereby, including the merger. See "Voting Agreement", "Security Ownership of Certain Beneficial Owners and Management" and the voting agreement included as Annex B to this proxy statement.

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Voting, Proxies and Revocation

Attending the Special Meeting

        All Company stockholders, including stockholders of record and stockholders who hold their shares through banks, brokers or other holders of record, are invited to attend the special meeting. Stockholders of record can vote in person at the special meeting. If you are not a stockholder of record, you must obtain a legal proxy executed in your favor from the record holder of your shares to be able to vote in person at the special meeting. If you plan to attend the special meeting, you must hold your shares in your own name or have a letter from the record holder of your shares confirming your ownership. In addition, you must bring a form of personal photo identification with you in order to be admitted to the meeting. The Company reserves the right to refuse admittance to anyone without proper proof of share ownership or without proper photo identification.

Voting by Stockholders of Record

        If you are a stockholder of record, you may have your shares of Company common stock voted on matters presented at the special meeting in any of the following ways:

•

by proxy—stockholders of record have a choice of submitting a proxy:



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by telephone or over the Internet, by accessing the telephone number or website specified on the enclosed proxy card;



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by signing, dating and returning the enclosed proxy card in the accompanying prepaid reply envelope; or



•

in person—you may attend the special meeting and cast your vote there.

Voting of Shares Held in "Street Name"; Broker Non-Votes

        If you are a beneficial owner of shares of Company common stock held in "street name," you should receive instructions from your bank, broker or other holder of record that you must follow in order to have your shares of Company common stock voted. Those instructions will identify which of the above choices are available to you in order to have your shares of Company common stock voted. If you have not received such voting instructions or require further information regarding such voting instructions, contact your broker. If your bank, broker or other holder of record holds your shares of Company common stock in "street name," such record holder will vote your shares of Company common stock only if you provide instructions on how to vote by filling out the voter instruction form sent to you by such record holder with this proxy statement. Please note that, if you are a beneficial owner of shares of Company common stock held in "street name" and wish to vote in person at the special meeting, you must provide a legal proxy executed in your favor from your bank, broker or other holder of record at the special meeting.

        Under stock exchange rules, banks, brokers and other holders of record who hold shares of Company common stock in "street name" for a beneficial owner of those shares typically have the authority to vote in their discretion on "routine" proposals when they have not received instructions from beneficial owners. However, such record holders are not allowed to exercise their voting discretion with respect to the approval of matters determined to be "non-routine." "Broker non-votes" are shares held in "street name" by banks, brokers and other holders of record that are present or represented by proxy at the special meeting, but for which the beneficial owner has not provided the record holder with instructions on how to vote on a particular proposal that such record holder does not have discretionary voting power on. Because, under applicable rules, banks, brokers and other holders of record holding shares in "street name" do not have discretionary voting authority with respect to any of the three proposals described in this proxy statement, if a beneficial owner of

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Company common stock held in "street name" does not give voting instructions to the applicable record holder, then those shares will not be counted as present in person or by proxy at the special meeting. As the vote to approve the merger proposal is based on the total number of shares of Company common stock outstanding at the close of business on the record date, if you fail to issue voting instructions to your bank, broker or other holder of record, it will have the same effect as a vote "AGAINST" the proposal to adopt the merger agreement. Although we do not expect to bring any matters before the meeting other than the three proposals described in this proxy statement, if an additional matter is brought before the meeting and is one on which brokers have discretionary voting authority and you fail to provide instructions to your broker with respect to the compensation proposal or the adjournment proposal, such broker non-votes will be counted for purposes of determining a quorum and have the same effect as a vote "AGAINST" such proposals.

Voting of Proxies; Incomplete Proxies

        If you submit a proxy, regardless of the method you choose to submit such proxy, the individuals named on the enclosed proxy card, and each of them, with full power of substitution, will vote your shares of Company common stock in the way that you indicate. When completing the Internet or telephone processes or the proxy card, you may specify whether your shares of Company common stock should be voted for or against, or may choose to abstain from voting, on all, some or none of the specific items of business to come before the special meeting.

        All shares represented by valid proxies that the Company receives through this solicitation, and that are not revoked, will be voted in accordance with your instructions on the proxy card. If you properly sign your proxy card but do not mark the boxes showing how your shares of Company common stock should be voted on a matter, the shares of Company common stock represented by your properly signed proxy will be voted in accordance with the recommendation of the Company board, which, as of the date of this proxy statement, are "FOR" the merger proposal, "FOR" the compensation proposal and "FOR" the adjournment proposal.

Deadline to Vote by Proxy

        Please refer to the instructions on your proxy or voting instruction card to determine the deadlines for submitting your proxy over the Internet or by telephone. If you choose to submit a proxy by mailing a proxy card, your proxy card should be mailed in the accompanying prepaid reply envelope and must be filed with our Corporate Secretary by the time the special meeting begins.

Revocation of Proxy

        If you are a stockholder of record of your shares of the Company's common stock, you have the right to revoke a proxy, whether delivered over the Internet, by telephone or by mail, at any time before the special meeting, by submitting a later-dated proxy through any of the methods available to you, by giving written notice of revocation to the Company's Corporate Secretary, which must be filed with the Corporate Secretary by 5:00 p.m. on the business day immediately prior to the date of the special meeting, or by attending the special meeting and voting in person. Attending the special meeting alone, without voting at the special meeting, will not be sufficient to revoke your proxy. Written notice of revocation should be mailed to: KCG Holdings, Inc., Attn: Corporate Secretary, 300 Vesey Street, New York, NY 10282.

        If you are a "street name" holder of the Company's common stock, you may change your vote by submitting new voting instructions to your bank, broker or other holder of record. You must contact the record holder of your shares to obtain instructions as to how to change your proxy vote.

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Solicitation of Proxies

        The Company is soliciting your proxy in conjunction with the merger. The Company will bear the cost of soliciting proxies from you. In addition to solicitation of proxies by mail, the Company will request that banks, brokers and other record holders send proxies and proxy material to the beneficial owners of Company common stock and secure their voting instructions. The Company has also made arrangements with Okapi Partners LLC to assist it in soliciting proxies and has agreed to pay Okapi Partners LLC approximately $8,500 plus reasonable expenses for these services.

Delivery of Proxy Materials to Stockholders Sharing an Address

        As permitted by the Exchange Act, only one copy of this proxy statement is being delivered to multiple Company stockholders sharing an address, unless the Company has previously received contrary instructions from one or more such stockholders. This is referred to as "householding." Stockholders who hold their shares in "street name" can request further information on householding through their banks, brokers or other holders of record. On written or oral request to the Company's proxy solicitor, Okapi Partners LLC, at 1212 Avenue of the Americas, 24^th Floor New York, New York 10036, or toll-free at (855) 208-8903 or direct at (212) 297-0720, or by email at KCGHoldings@okapipartners.com, the Company will deliver promptly a separate copy of this document to a stockholder at a shared address to which a single copy of the document was delivered.

Questions and Additional Information

        If you have more questions about the merger or how to submit your proxy, or if you need additional copies of this proxy statement or the enclosed proxy card or voting instructions, please contact KCG Holdings, Inc., Investor Relations, 300 Vesey Street, New York, NY 10282, or at (646) 682-6000, or the Company's proxy solicitor, Okapi Partners LLC, at 1212 Avenue of the Americas, 24^th Floor New York, New York 10036, or toll-free at (855) 208-8903 or direct at (212) 297-0720, or by email at KCGHoldings@okapipartners.com.

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PARTIES TO THE MERGER

The Company

KCG Holdings, Inc.
300 Vesey Street
New York, NY 10282
Telephone: (646) 682-6000

        KCG Holdings, Inc., a Delaware corporation, is a leading independent securities firm offering clients a range of services designed to address trading needs across asset classes, product types and time zones. The Company combines advanced technology with specialized client service across market making, agency execution and trading venues and also engages in principal trading via exchange-based electronic market making. The Company has multiple access points to trade global equities, options, fixed income, currencies and commodities via voice or automated execution. Shares of Company common stock are listed on the NYSE under the symbol "KCG."

        Additional information about the Company and its subsidiaries is included in documents incorporated by reference in this proxy statement. See "Where You Can Find More Information." The Company maintains a website at http://www.kcg.com. The information provided on the Company's website is not part of this proxy statement and is not incorporated by reference.

Virtu

Virtu Financial, Inc.
900 Third Ave., 29^th Floor
New York, NY 10022
Telephone: (212) 418-0100

        Virtu Financial, Inc. is a leading technology-enabled market maker and liquidity provider to the global financial markets. Virtu generates revenue by buying and selling securities and other financial instruments and earning small amounts of money on individual transactions based on the difference between what buyers are willing to pay and what sellers are willing to accept, often referred to as "bid/ask spreads," across a large volume of transactions. Virtu makes markets by providing quotations to buyers and sellers in more than 12,000 securities and other financial instruments on more than 235 unique exchanges, markets and liquidity pools in 36 countries around the world. Virtu also generates revenue by using its proprietary technology to earn technology services revenue, by providing technology infrastructure and agency execution services to select third parties. Virtu's shares of its Class A common stock are listed on the NASDAQ under the symbol "VIRT."

Merger Sub

Orchestra Merger Sub, Inc.
c/o Virtu Financial, Inc.
900 Third Ave., 29^th Floor
New York, NY 10022
Telephone: (212) 418-0100

        Orchestra Merger Sub, Inc. is a Delaware corporation and an indirect, wholly owned subsidiary of Virtu. Merger Sub was incorporated on April 17, 2017 for the sole purpose of effecting the merger. As of the date of this proxy statement, Merger Sub has not conducted any activities other than those incidental to its incorporation, the execution of the merger agreement and the transactions contemplated by the merger agreement.

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THE MERGER

        This discussion of the merger is qualified in its entirety by reference to the merger agreement, which is attached to this proxy statement as Annex A. You should read the entire merger agreement carefully as it is the legal document that governs the merger.

Terms of the Merger

        Each of the Company's and Virtu's respective boards of directors has unanimously approved the merger agreement and the merger. Under the merger agreement, Merger Sub, an indirect wholly owned subsidiary of Virtu, will merge with and into the Company, so that the Company will be the surviving entity in the merger and will be an indirect wholly owned subsidiary of Virtu when the merger is completed.

        In the merger, each share of Company common stock issued and outstanding immediately prior to the effective time, except for specified shares held by the Company or owned by Virtu or Merger Sub and shares of Company common stock held by Company stockholders who properly exercise dissenters' rights, shall be converted into the right to receive $20.00 in cash without interest. For a discussion of the treatment of awards outstanding under the Company stock plan as of the effective time and the treatment of Company warrants outstanding as of the effective time, see "The Merger Agreement—Treatment of Company Equity Awards" and "The Merger Agreement—Treatment of Company Warrants," respectively.

        Company stockholders are being asked to adopt the merger agreement. See "The Merger Agreement" for additional and more detailed information regarding the legal documents that govern the merger, including information about conditions to the completion of the merger and provisions for terminating or amending the merger agreement.

Background of the Merger

        Jefferies is the Company's largest shareholder, with beneficial ownership of approximately 24.5% of the outstanding Company common stock at the time that the Company and Virtu entered into the merger agreement. Jefferies does not have a representative on the Company board. On February 21, 2017, Richard Handler, the chief executive officer and chairman of Jefferies, met with Daniel Coleman, the chief executive officer of the Company, and advised him of Virtu's interest in acquiring the Company, and that Virtu would be making a formal offer.

        In December 2016 and again in mid-February 2017, representatives of Virtu had indicated to Mr. Handler Virtu's possible interest in the Company in a series of conversations initiated by representatives of Virtu. Jefferies informed the Company that, during these conversations, a representative of Virtu communicated to Mr. Handler preliminary ranges of prices per share at which Virtu might consider making a proposal to acquire the Company, and the Company has been informed by Jefferies that, on each occasion, Mr. Handler indicated to Virtu that he could not speak for the Company. In addition, Jefferies informed the Company that, on February 14, 2017, at Mr. Handler's suggestion, a managing director in investment banking at Jefferies met with Douglas Cifu, Virtu's chief executive officer, Joseph Molluso, Virtu's chief financial officer, and other Virtu representatives to discuss the Company.

        On February 23, 2017, Mr. Cifu, on behalf of Virtu, delivered to Mr. Coleman, on behalf of the Company, a written proposal to acquire the Company through a merger transaction at a price in the range of $18.50 to $20.00 per share in cash. The closing price of the Company common stock on the NYSE on February 23, 2017 was $14.31.

        On February 24, 2017, Mr. Coleman sent a response to Mr. Cifu confirming receipt of the proposal and stating that the Company board would review the proposal and consider next steps.

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        On February 26, 2017, the Company board convened to discuss the proposal from Virtu and to consider other strategic opportunities that might be available to the Company. Representatives of Sullivan & Cromwell LLP ("Sullivan & Cromwell"), the Company's legal advisor, also attended the meeting. At the meeting, Mr. Coleman introduced to the Company board a proposed plan to restructure certain aspects of the Company's business and return capital to its shareholders without pursuing a merger or sale of the Company (which we refer to as the "Restructuring Plan") and explained that the Company's management had been working on the Restructuring Plan for several months and that the offer had caused management to accelerate its thinking about the timing of any restructuring. He recommended that the Company board hire an independent financial advisor to advise the Company in connection with considering its strategic alternatives, including a transaction with Virtu. To facilitate that objective, the Company board established a sub-committee to meet with potential independent financial advisors and appointed directors James Milde (chair), Rene Kern, Heather Tookes and Alastair Rampell as its members. The sub-committee had an informal meeting on March 1, 2017 to discuss potential financial advisors for the sub-committee to interview.

        On March 6, 2017, members of the sub-committee, along with representatives of the Company's management team and representatives of Sullivan & Cromwell, met with two possible financial advisors, including Goldman Sachs, to discuss a potential engagement. Later on March 6, 2017, the committee decided to recommend to the Company board that it engage Goldman Sachs to serve as the independent financial advisor to the Company board.

        On March 7, 2017, Mr. Handler and other representatives of Jefferies spoke to Mr. Coleman about the Virtu offer. Mr. Handler encouraged the Company to engage with Virtu.

        On March 10, 2017, the Company board met with the Company's management and representatives of Goldman Sachs and Sullivan & Cromwell. Mr. Coleman provided an update on his communications with Mr. Cifu since the February 26, 2017 board meeting and presented to the Company board additional information about the Restructuring Plan. Representatives of Sullivan & Cromwell provided an outline of the Company board's fiduciary duties and legal considerations, including standards established under Delaware law for a transaction of this sort, related to the Virtu proposal. Goldman Sachs presented to the Company board a proposed near term action plan and list of considerations for a response to Virtu and its preliminary financial analysis of the Virtu bid and Virtu's ability to finance the transaction and shareholder considerations. At this meeting, the Company board determined to postpone any formal response to Virtu until after its next meeting on March 15, 2017 when the Restructuring Plan would be discussed in greater detail.

        On March 14, 2017, Mr. Coleman met with Mr. Handler who reiterated to Mr. Coleman Jefferies' view that the Company should engage in discussions with Virtu regarding its proposal. On the same day, Charles E. Haldeman, the chairman of the Company board, spoke to Brian Friedman, the chairman of the executive committee of Jefferies, who reaffirmed Jefferies' view that the Company should engage in discussions with Virtu regarding its proposal.

        On March 15, 2017, the Company board met with the Company's management and representatives of Goldman Sachs and Sullivan & Cromwell. Investment banking personnel from Jefferies, who had assisted the Company in developing the Restructuring Plan, attended the initial part of the meeting where the Restructuring Plan was discussed. Mr. Coleman presented the Restructuring Plan to the Company board. Representatives of Goldman Sachs presented a preliminary financial analysis of the Company, including analysis using the Restructuring Plan, and a preliminary financial analysis of the Virtu proposal, and provided an update on the transaction process and a preliminary list of other potential strategic buyers.

        Later on March 15, 2017, various news outlets including The Wall Street Journal and Dow Jones Newswires published articles disclosing that Virtu had made an unsolicited offer to purchase the Company. On the day of the publication of The Wall Street Journal article, the Company's stock price

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rose from $13.73 when markets opened to $16.90 when NYSE suspended trading in the stock prior to the market closing.

        Later in the day on March 15, 2017, Mr. Coleman sent a letter to Mr. Cifu responding to the initial Virtu proposal. Mr. Coleman informed Mr. Cifu that the Company board had been actively considering the Virtu proposal and offered to meet with Mr. Cifu to discuss the proposal and possible next steps. He asked Mr. Cifu whether Virtu was prepared to increase its offer price, and requested that Mr. Cifu provide additional detail on key execution risks related to the proposed transaction, in particular the financing, and outline Virtu's plans with respect to retention of Company employees and Virtu's plans for financing the merger. On the same day, the Company issued a press release confirming that it had received an unsolicited proposal from Virtu to acquire all of the outstanding Company common stock for $18.50 to $20.00 per share in cash.

        On March 16, 2017, Virtu issued a press release confirming that it had made an offer to acquire the Company.

        Later in the day on March 16, 2017, Mr. Cifu sent a letter to Mr. Coleman responding to Mr. Coleman's March 15 letter. Mr. Cifu affirmed the price range of $18.50 to $20.00, and affirmed that Virtu did not expect to have a financing condition at the time of signing a definitive agreement and had had preliminary conversations with J.P. Morgan regarding debt financing for a possible transaction with the Company. He asserted that a preliminary evaluation by counsel indicated that required regulatory approvals, including antitrust approval, would not present an obstacle to a possible transaction. Finally, he indicated that Virtu would be willing to enter into a non-disclosure agreement, or NDA, including a standstill agreement with the Company in order to commence its diligence process and appended a draft NDA to his letter.

        Also on March 16, 2017, a party, which we refer to as Party A, that had apparently learned about the transaction from the press coverage of Virtu's proposal, contacted Mr. Coleman to inform him that it was interested in exploring a strategic combination with the Company.

        On March 17, 2017, the Company and Virtu entered into an NDA. Virtu sent the Company a list of requested materials and information about the Company and proposed a series of meetings among members of the management teams of Virtu and the Company.

        On March 20, 2017, the Company board met to receive an update on the process, including a description of the inbound interest from Party A and information about the Virtu proposal.

        Representatives of Virtu received access to the Company's data room on March 20, 2017. Between March 21 and April 5, 2017, representatives of Virtu, J.P. Morgan and Sandler O'Neill + Partners, L.P., Virtu's financial advisors, together with Virtu's financial, accounting and legal advisors, attended numerous management due diligence sessions with representatives of the Company and its advisors.

        On March 22, 2017, the Company entered into an NDA including a standstill agreement without a provision restricting waiver requests with Party A. Party A received access to the Company's data room on the same day. Party A attended management diligence sessions with members of the Company's management team on March 23, 2017.

        Although the Company did receive limited inquiries from parties indicating preliminary interest in acquiring immaterial assets or businesses of the Company, Party A was the only party to contact the Company or its advisors regarding an acquisition of the Company after the March 15 Wall Street Journal article and subsequent press releases from the Company and Virtu. On March 23, 2017, following discussions with Mr. Coleman, representatives of Goldman Sachs and representatives of Sullivan & Cromwell, Mr. Haldeman contacted the members of the Company board to recommend that Goldman Sachs, on the Company's behalf, reach out to other possible bidders for the Company initially

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identified by Goldman Sachs and approved by Mr. Haldeman and the Company's management. The board members approved his recommendation.

        On March 24, 2017, Party A informed Mr. Coleman that it was no longer interested in pursuing a possible transaction with the Company.

        On March 24 and 26, 2017, representatives of Goldman Sachs contacted representatives of J.P. Morgan to discuss Virtu's ongoing due diligence process and certain matters related to Virtu's evaluation of the Company. On March 26, 2017, pursuant to instructions from the Company, Goldman Sachs requested that Virtu deliver to the Company no later than April 3, 2017 its best and final offer, including a draft merger agreement, draft financing commitment agreements with Virtu's committed financing counterparties, a summary statement of the sources and uses of financing Virtu intended to use to acquire the Company and a list of final due diligence items. Goldman Sachs, at the Company's request, advised J.P. Morgan that, if the Company board approved Virtu's revised offer, the Company would seek to sign a definitive merger agreement and announce the transaction with Virtu no later than April 20, 2017, the date of the Company's first quarter earnings announcement.

        On March 27, 2017, pursuant to instructions from the Company, Goldman Sachs began to contact other possible bidders.

        On March 29, 2017, the Company board received an update from representatives of Goldman Sachs on their outreach to other possible bidders and to discuss other matters related to a possible transaction with Virtu. Goldman Sachs reported that it had contacted six possible bidders and that one, which we refer to as Party B, had expressed interest in receiving more information about the Company. The remainder indicated that they were not interested in a transaction with the Company.

        On March 29, 2017, Mr. Cifu, on behalf of Virtu, sent Mr. Coleman a letter advising him of the significant progress made by Virtu in its due diligence process and thanking the Company's management team for its thorough commitment to the diligence process to date. He highlighted certain open diligence matters and proposed that Virtu would deliver a revised offer price, draft transaction documents and a draft commitment letter from J.P. Morgan with respect to the financing of a possible acquisition of the Company by Virtu no later than April 10, 2017.

        On March 30, 2017, in a letter from Mr. Coleman to Mr. Cifu, the Company agreed to Virtu's proposed timeline for a revised offer and draft documentation.

        Party B withdrew its interest in pursuing an acquisition of the Company on March 31, 2017 prior to entering into an NDA.

        On April 4, 2017, the sub-committee of the board met to discuss the terms of the proposed engagement letter with Goldman Sachs. Members of management also attended.

        On April 10, 2017, Virtu sent the Company and its representatives draft transaction agreements, including a draft merger agreement, draft debt financing commitment letter from J.P. Morgan and a draft voting agreement between Jefferies and Virtu, and a revised proposal to acquire the Company for $18.50 a share in an all cash transaction. The Company board scheduled a meeting for the afternoon of April 11, 2017 to discuss Virtu's revised bid.

        Prior to the April 11, 2017 board meeting, a representative of J.P. Morgan communicated to a representative of Goldman Sachs, and representatives of Jefferies communicated to both Mr. Haldeman and Mr. Coleman, their belief that $18.50 per share was not necessarily Virtu's best and final offer and that Virtu could be willing to offer a higher price for the Company.

        At its April 11, 2017 meeting, the Company board rejected Virtu's revised proposal to acquire the Company for $18.50 per share, but decided to ask Virtu for what would be considered by the Company board as Virtu's best and final offer. Representatives of Goldman Sachs presented a preliminary

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financial analysis of the Company, including analysis using the proposed Restructuring Plan. Representatives of Sullivan & Cromwell presented with respect to various legal matters.

        On April 12, 2017, the Company received a revised bid from Virtu to acquire the Company in an all cash transaction for $20.00 per share.

        At a meeting on April 12, 2017, the Company board discussed Virtu's revised proposal. The Company board agreed to respond to Virtu's April 12 proposal with a counter-offer for a purchase price of $20.21 per share, the book value per share of the Company as at March 31, 2017. The Company board also discussed, with representatives of Sullivan & Cromwell and Goldman Sachs and management, several contractual points related to reducing regulatory risk, retaining employees in the period between signing an agreement and completing a transaction with Virtu and seeking to ensure a high degree of certainty that the transaction would be completed if the Company entered into an agreement with Virtu. The Company board determined that Goldman Sachs would convey its response to the Virtu April 12 proposal in a discussion with J.P. Morgan that evening.

        On April 15, 2017, Sullivan & Cromwell sent a revised draft of the merger agreement to Paul, Weiss, Rifkind, Wharton & Garrison LLP ("Paul Weiss"), counsel to Virtu. On April 16, 2017, Sullivan & Cromwell sent additional revisions of the draft of the merger agreement to Paul Weiss. Later in the day on April 16, 2017, Paul Weiss sent a revised draft of the agreement to Sullivan & Cromwell.

        The Company board, with members of the Company's management and representatives from Goldman Sachs and Sullivan & Cromwell, convened on April 17, 2017 to discuss the status of the proposed transaction with Virtu. Representatives of Goldman Sachs reported that J.P. Morgan had informed Goldman Sachs that, after considering the Company's counter-proposal of $20.21 per share, Virtu was unwilling to increase its offer per share above $20.00 and that Virtu had $750 million of committed equity financing and that J.P. Morgan would provide the remainder of the financing, which would be borrowings, that Virtu required to acquire the Company. Representatives of Sullivan & Cromwell provided an update on the status of the negotiation of the merger agreement with Paul Weiss.

        The Company board met again, with members of the Company's management and representatives of Goldman Sachs and Sullivan & Cromwell, on the morning of April 19, 2017 to discuss the progress towards a final merger agreement with Virtu. The Company board instructed its advisors to attempt to finalize all transaction documentation in order for the Company to be in a position to sign the merger agreement and announce the acquisition of the Company by Virtu on April 20 in connection with the Company's earnings announcement. Understanding that Virtu had refused to increase its offer price above $20.00 per share, the Company board tentatively agreed to a purchase price equal to $20.00 a share, subject to receipt of a fairness opinion from Goldman Sachs, satisfactory resolution of open points on the merger agreement and delivery of final committed financing documents.

        On April 19, 2017, acting by written consent, the Company board unanimously approved the Forecasts (as defined in "The Merger—Opinion of the Company's Financial Advisor") of the Company used in connection with the Restructuring Plan, but not the execution of the Restructuring Plan, and the use of such Forecasts in the financial analysis by Goldman Sachs of the transaction with Virtu.

        Following the Company board meeting on April 19, 2017 and through the morning of April 20, 2017, representatives of Sullivan & Cromwell and Paul Weiss continued to negotiate and finalize the terms of the draft merger agreement.

        On the morning of April 20, 2017, the Company board convened, with members of the Company's management and representatives of Sullivan & Cromwell and Goldman Sachs, to discuss updates since the April 19 board meeting and the negotiation of the definitive documentation. Goldman Sachs then presented to the Company board its financial analyses with respect to the Company and the proposed

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transaction with Virtu. Thereafter, at the request of the Company board, Goldman Sachs rendered its oral opinion to the Company board (which was subsequently confirmed in writing by delivery of Goldman Sachs' written opinion to the Company board dated the same date) to the effect that, as of April 20, 2017, and based upon and subject to the assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, the merger consideration to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement was fair, from a financial point of view, to such holders. Sullivan & Cromwell provided a summary of the terms of the merger agreement and gave a further presentation describing the fiduciary duties of the directors in approving the Company entering into the merger agreement.

        Following the rendering of Goldman Sachs' opinion, and extensive review and discussions among the members of the Company board, including consideration of the factors described under "—Reasons for the Merger; Recommendation of the Company Board", the Company board, with all members present and voting, unanimously determined that the merger agreement and the merger are fair to and in the best interests of the Company and its stockholders and unanimously approved the merger agreement and the merger and declared it advisable that the Company enter into the merger agreement. The Company board further resolved unanimously to recommend approval and adoption by the Company stockholders of the merger agreement, the merger and such other matters that are submitted for their approval in connection with the merger agreement. The Company board then directed Company management to execute a definitive merger agreement on substantially the terms reviewed at the board meeting, and directed that the merger agreement be submitted to the Company stockholders for approval.

        At the same time that the Company entered into the merger agreement, at the request of Virtu, Jefferies entered into a voting agreement with Virtu pursuant to which it agreed to vote all of the shares of the Company common stock that it is entitled to vote in favor of the merger agreement proposal.

        On the morning of April 20, 2017, Virtu and the Company each issued a press release announcing the execution of the merger agreement.

Reasons for the Merger; Recommendation of the Company Board of Directors

        In determining that the merger agreement and the merger are fair to and in the best interests of the Company and the Company stockholders, approving the merger agreement and the merger and declaring it advisable that the Company enter into the merger agreement, and recommending approval and adoption by the Company stockholders of the merger agreement, the merger and any other matters submitted for their approval in connection with the merger agreement, the Company board consulted with Company management, as well as its financial and legal advisors, and considered numerous factors, including the following material factors:

•

the value to be received by the stockholders in the merger, including the fact that the cash consideration to be received by the stockholders represented a significant premium relative to the trading price of Company common stock prior to the public announcement of the Virtu offer, and a premium higher than the median premium achieved in comparable transactions in each of the last five years. The merger consideration represents a premium of approximately 45.7% over $13.73, the closing price of Company common stock on the NYSE on March 14, 2017, the last trading day prior to the date on which a news organization reported publicly that Virtu had made an offer to purchase the Company, and a premium of approximately 12.7% over $17.74, the closing price of Company common stock on the NYSE on April 19, 2017, the last trading day prior to the public announcement of the merger agreement;

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•

the possibility that, if the Company did not enter into the merger agreement, it could take a considerable amount of time before, and involve a substantial amount of risk as to whether, the trading price of Company common stock would reach and sustain the $20.00 per share merger consideration, as adjusted for present value;



•

the belief of the Company board that, as a result of the negotiations between the parties, the merger consideration of $20.00 per share was the highest price per share for Company common stock that Virtu was willing to pay at the time of those negotiations, and that Virtu's agreement to pay that price would result in a sale of the Company at the highest price per share for Company common stock that was reasonably attainable, particularly in view of the fact that no other parties approached the Company with a proposal for a transaction at a higher price, even after the public disclosure of Virtu's bid range, and in spite of the Company's efforts to solicit other proposals through Goldman Sachs;



•

the possibility that, if the Company did not enter into the merger agreement, there would not be another opportunity for the Company's stockholders to receive as high or a higher price as a result of a sale of the Company within at least the intermediate future, in light of the belief of the Company board that there are apparently few, if any, parties that would be willing to offer more than Virtu's current offer, as demonstrated by the fact that, of the six parties that were contacted by Goldman Sachs regarding a possible combination, and Party A which contacted the Company directly and without solicitation, only Virtu was prepared to make a proposal at that time, with the rest of the parties expressing no interest or initially expressing interest but withdrawing shortly thereafter;



•

the financial analyses reviewed and discussed with the Company board by representatives of Goldman Sachs;



•

the oral opinion of Goldman Sachs rendered to the Company board on April 20, 2017 (which was subsequently confirmed in writing by delivery of Goldman Sachs' written opinion to the Company board dated the same date) to the effect that, as of April 20, 2017, and based upon and subject to the assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, the merger consideration to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement was fair, from a financial point of view, to such holders. The opinion of Goldman Sachs is more fully described in the section entitled "—Opinion of Goldman Sachs & Co. LLC" beginning on page 31 and the full text of such opinion is attached to this proxy statement as Annex C;



•

the fact that the merger consideration is to be paid entirely in cash, which will allow the Company's stockholders to realize, upon the closing, a certainty of value and liquidity relative to the market, economic and other risks that arise from receiving an equity interest in a public company;



•

the availability of appraisal rights under Delaware law to Company stockholders who do not vote in favor of the adoption of the merger agreement and comply with all of the required procedures under Delaware law for the perfection of such appraisal rights, which rights provide eligible stockholders with an opportunity to have the Delaware Court of Chancery determine the fair value of their shares, which may be more than, less than or the same as the amount such stockholders would have received under the merger agreement;



•

its multiple reviews and discussions with Company management and financial and legal advisors;



•

its understanding of the current and prospective environment in which the Company operates, including the performance of and dynamics affecting electronic securities trading and the capital markets more generally (including the persistence of low volatility in capital markets in the

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period prior to the Company's receipt of Virtu's initial proposal), national and local economic conditions, compression of profit margins in the industries in which the Company operates and the likely effect of these factors on the Company and the proposed Restructuring Plan both with and without the proposed merger;

•

the extensive review undertaken by the Company board and Company management, with the assistance of financial and legal advisors, with respect to the Company's strategic outlook and the strategic alternatives available to the Company and the Company board's determination that the transaction with Virtu was more favorable to Company stockholders than the potential value that might result from other alternatives reasonably available to the Company, including the Restructuring Plan, based on factors including, but not limited to:



•

the inquiries by Goldman Sachs regarding a possible combination with six other parties and the likelihood of an alternative transaction emerging and that no parties other than Party A approached the Company after the Virtu bid was made public;



•

the persistence of low market volatility in the 12-15 months prior to the Company's receipt of Virtu's initial proposal, which has put pressure on the Company's financial performance, and the observation that the Company's trading strategies are more likely to perform well in market environments that have moderate-to-high volatility;



•

the risk that the Company would not achieve the revenue growth projected in the Restructuring Plan and the risk that the Company would fail to implement one or more transactions contemplated by the Restructuring Plan, including a proposal to refinance certain outstanding debt of the Company and to return capital to shareholders;



•

the value of and challenges facing the Company as an independent company; and



•

the capital and earnings available to the Company as an independent company, at the time and as expected in the future, to pursue various business and strategic initiatives;



•

the fact that the terms and conditions of the merger agreement, including, but not limited to, the representations, warranties and covenants of the parties, the conditions to closing and the form of the merger consideration, are reasonable and comparable to those in other recent acquisition transactions;



•

the fact that the terms of the merger agreement provide that, under certain circumstances, the Company is permitted to consider unsolicited acquisition proposals, withdraw its approval or recommendation with respect to the merger agreement or terminate the merger agreement, subject, in each case, to compliance with certain procedural requirements, which may include the payment of a $45 million termination fee;



•

the size of the termination fee in relation to the overall transaction size (i.e., approximately 3.5% of the transaction consideration) and the belief of the Company board that the $45 million termination fee was unlikely to preclude another party that was interested in acquiring the Company from making an acquisition proposal for the Company;



•

the absence of any financing condition or contingency to the merger and the fact that Virtu provided evidence of committed sources of equity and debt financing that would enable it to consummate the merger;



•

the outside date under the merger agreement on which either party, subject to certain exceptions, can terminate the merger agreement allowing for sufficient time to consummate the merger;



•

Virtu's commitments in the merger agreement to use its reasonable best efforts to consummate the proposed merger (subject to the terms and conditions of the merger agreement), including

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to use its reasonable best efforts to obtain promptly all required regulatory approvals and to obtain alternative financing if necessary; and

•

the regulatory and other approvals in connection with the proposed transaction and the expected likelihood that such regulatory approvals will be received in a reasonably timely manner.

        The Company board also considered the potential risks and other potentially negative factors related to the merger agreement and the merger, but concluded that the anticipated benefits of the merger were likely to substantially outweigh these risks. These potential risks included:

•

the amount of time it could take to complete the merger, primarily to obtain regulatory approvals and to obtain Company stockholder approval, and transaction-related costs;



•

the fact that some of the Company's directors and executive officers have other interests in the merger that are in addition to their interests as stockholders of the Company, including as a result of employment and compensation arrangements with the Company (see "The Merger—Interests of Certain Persons in the Merger");



•

the risks and costs to the Company if the merger does not close, including the potential risk of diverting management and employee attention and resources from the operation of Company business and towards the completion of the merger, potential employee attrition and the potential effects on business relationships, including with customers and counterparties, and potential customers and counterparties;



•

the possibility that not all conditions to the closing of the merger, including the receipt of the necessary stockholder approval and regulatory approvals, may be satisfied or waived such that the merger may be delayed or may not be consummated;



•

the possibility that the following factors, either individually or in combination, could discourage potential acquirers from making a competing bid to acquire the Company: (i) the restrictions in the merger agreement on the Company's ability to solicit or engage in discussions or negotiations with any third parties regarding acquisition proposals; (ii) the requirement that, unless the merger agreement is terminated, the Company must convene the special meeting and submit the merger agreement to Company stockholders even if the Company board has withdrawn the Company recommendation for the merger proposal; (iii) the fact that Jefferies has entered into a voting agreement with Virtu pursuant to which it has agreed, among other things, to vote all of the shares of Company common stock that it is entitled to vote in favor of the merger agreement even if the Company board has withdrawn the Company recommendation; (iv) the risk of employee attrition, including the loss of key employees following the announcement of the merger; and (v) the requirement that, in connection with a termination of the merger agreement in certain circumstances and subject to the terms and conditions of the merger agreement, the Company could be required to pay Virtu a $45 million termination fee or up to $15 million in expense reimbursements;



•

the fact that the all-cash merger consideration, while providing certainty of value and liquidity upon consummation of the merger, would not allow Company stockholders to participate in any future earnings growth of the combined company after the merger or benefit from any future increase in its value;



•

the possible effect of any suit, action or proceeding in respect of the merger agreement or the transactions contemplated by the merger agreement;



•

the fact that the receipt of the merger consideration in exchange for Company common stock pursuant to the merger would be a taxable transaction for U.S. federal income tax purposes; and

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•

the fact that restrictions on the conduct of the Company's business prior to completion of the merger could delay or prevent the Company from undertaking business opportunities that arise pending completion of the merger, which opportunities might be lost to the Company if the merger could not be completed.

        The foregoing discussion of the information and factors considered by the Company board is not intended to be exhaustive, but rather includes the material factors considered by the Company board. In determining that the merger agreement and the merger are fair to and in the best interests of the Company and the Company stockholders, approving the merger agreement and the merger and declaring it advisable that the Company enter into the merger agreement, and recommending approval and adoption by the Company stockholders of the merger agreement, the merger and any other matters submitted for their approval in connection with the merger agreement, the Company board did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The Company board considered all these factors as a whole, including discussions with, and questioning of, Company management and the Company's independent financial and legal advisors, and overall considered the factors to be favorable to, and to support, its determination.

Unaudited Prospective Financial Information

        The Company does not as a matter of course make public projections as to future performance, revenues, earnings or other financial results due to, among other reasons, the uncertainty of the underlying assumptions and estimates. As a result, the Company does not endorse the unaudited prospective financial information as a reliable indicator of future results. The Company is including in this proxy statement a summary of certain unaudited prospective financial information that was provided to the Company board, to Goldman Sachs, the financial advisor to the Company, for use in providing financial advice to the Company board, and to Virtu. The inclusion of this information should not be regarded as an indication that any of the Company, Goldman Sachs, Virtu, their respective representatives or any other recipient of this information considered, or now considers, it to be predictive of actual future results, or that it should be construed as financial guidance, and it should not be relied on as such. Company management, with the approval of the Company board, directed Goldman Sachs to use the unaudited prospective financial information with respect to the Company in connection with (i) the preparation of the financial analyses Goldman Sachs reviewed and discussed with the Company board at its meeting on April 20, 2017 and (ii) the preparation of Goldman Sachs' opinion rendered orally to the Company board at that meeting. The only projections used by the Company board in resolving to approve the merger were the Forecasts (as defined in "—Opinion of Goldman Sachs & Co. LLC"), and Goldman Sachs did not use or rely on any projections other than those included in the Forecasts to perform any of the financial analyses described in the preceding sentence.

        The unaudited prospective financial information reflects the Restructuring Plan described under "—Background of the Merger." The Restructuring Plan includes numerous assumptions about future performance, as well as assumptions regarding the Company's ability to significantly reduce expenses, release significant trapped capital, refinance its existing indebtedness and return capital to the Company stockholders. The Company board has not approved execution of the Restructuring Plan but has approved the Forecasts included therein for use by Goldman Sachs, the financial advisor to the Company, for use in providing financial advice to the Company board.

        Actual results may differ materially from those set forth below, and important factors that may affect actual results and cause the unaudited prospective financial information to be inaccurate include, but are not limited to, risks and uncertainties relating to the Company's business, industry performance, general business, market and economic conditions, customer requirements, competition and adverse changes in applicable laws, regulations or rules. For other factors that could cause actual results to

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differ, please see the section entitled "Cautionary Statement Concerning Forward-Looking Statements" in this proxy statement and the sections entitled "Risk Factors" and "Cautionary Statement Regarding Forward-Looking Information" in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2016, the Company's Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017 and the other reports filed by the Company with the SEC.

        The unaudited prospective financial information does not take into account any circumstances or events occurring after the date it was prepared. The Company can give no assurance that, had the unaudited prospective financial information been prepared as of the date of this proxy statement, similar estimates and assumptions would be used. The Company does not intend to, and disclaims any obligation to, make publicly available any update or other revision to the unaudited prospective financial information to reflect circumstances existing since its preparation or to reflect the occurrence of unanticipated events, even in the event that any or all of the assumptions underlying the unaudited prospective financial information are shown to be in error, or to reflect changes in general economic or industry conditions. The unaudited prospective financial information does not take into account the possible financial and other effects on the Company of the merger and does not attempt to predict or suggest future results of the combined company. The unaudited prospective financial information does not give effect to the merger, including the impact of negotiating or executing the merger agreement, the expenses that may be incurred in connection with consummating the merger, the potential synergies that may be achieved by the combined company as a result of the merger or the effect of any business or strategic decisions or actions which would likely have been taken if the merger agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the merger. Further, the unaudited prospective financial information does not take into account the effect on the Company of any possible failure of the merger to occur. None of the Company, Goldman Sachs or their respective affiliates, officers, directors, advisors or other representatives has made, makes or is authorized in the future to make any representation to any Company stockholder or other person regarding the Company's ultimate performance compared to the information contained in the unaudited prospective financial information or that the forecasted results will be achieved. The summary of the unaudited prospective financial information included below is being provided solely because it was made available to the Company board, Virtu (with respect to certain of the information) and Goldman Sachs, the financial advisor to the Company, for use in providing financial advice to the Company board, and not to influence your decision as to whether to vote for the merger proposal or take any action in connection with the merger or your ownership of shares.

        The following table summarizes selected unaudited prospective financial data per the Restructuring Plan for the fiscal years ending December 31, 2017 through December 31, 2021.

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        While presented with numeric specificity, the unaudited prospective financial information reflects numerous estimates and assumptions made with respect to business, economic, market, competition, regulatory and financial conditions and matters specific to the Company's business, all of which are difficult to predict and many of which are beyond the Company's control. For example, for purposes of the Restructuring Plan, management of the Company assumed an effective tax rate of approximately 38%. The unaudited prospective financial information reflects both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. The Company can give no assurance that the unaudited prospective financial information or the underlying estimates and assumptions will be realized. In addition, since the unaudited prospective financial information covers multiple years, such information by its nature becomes less predictive with each successive year. Furthermore, the unaudited prospective financial information should not be construed as commentary by Company management as to how Company management expects the Company's actual results to compare to Wall Street research analysts' estimates, as to which the Company expresses no view.

        The unaudited prospective financial information was not prepared with a view toward public disclosure, nor was it prepared with a view toward compliance with GAAP, published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information. Neither the Company's independent registered public accounting firm, nor any other independent accountants, have compiled, examined or performed any procedures with respect to the unaudited prospective financial information contained herein, nor have they expressed any opinion or any other form of assurance on such information or its achievability. The independent registered public accountant reports incorporated by reference into this proxy statement relate to the Company's historical financial information. They do not extend to the unaudited prospective financial information and should not be read to do so.

        In light of the foregoing, and considering that the Company's special meeting will be held after the unaudited prospective financial information was prepared, as well as the uncertainties inherent in any forecasted information, Company stockholders are cautioned not to place unwarranted reliance on such information, and the Company urges all Company stockholders to review the Company's most recent SEC filings for a description of the Company's reported financial results. See "Where You Can Find More Information."

Opinion of Goldman Sachs & Co. LLC

        Goldman Sachs rendered its opinion to the Company board that, as of April 20, 2017 and based upon and subject to the factors and assumptions set forth therein, the $20.00 in cash per share of Company common stock to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement was fair from a financial point of view to such holders.

        The full text of the written opinion of Goldman Sachs, dated April 20, 2017, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex C. Goldman Sachs provided its opinion for the information and assistance of the Company board in connection with its consideration of the merger.

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The Goldman Sachs opinion is not a recommendation as to how any holder of Company common stock should vote with respect to the merger, or any other matter.

        In connection with rendering the opinion described above and performing its related financial analyses, Goldman Sachs reviewed, among other things:

•

the merger agreement;



•

annual reports to stockholders and Annual Reports on Form 10-K of the Company for the four fiscal years ended December 31, 2016;



•

the Company's Registration Statement on Form S-4, including the prospectus contained therein dated May 28, 2013 relating to the merger of Knight Capital Group, Inc. and GETCO Holding Company, LLC;



•

certain interim reports to stockholders and Quarterly Reports on Form 10-Q of the Company;



•

certain other communications from the Company to its stockholders;



•

certain publicly available research analyst reports for the Company; and



•

certain internal financial analyses and forecasts for the Company prepared by its management, as approved for Goldman Sachs' use by the Company, which are referred to as the "Forecasts".

        Goldman Sachs also held discussions with members of the senior management of the Company regarding their assessment of the past and current business operations, financial condition and future prospects of the Company; reviewed the reported price and trading activity for the shares of Company common stock; compared certain financial and stock market information for the Company with similar information for certain other companies the securities of which are publicly traded; reviewed the financial terms of certain recent business combinations in the electronic trading industry and in other industries; and performed such other studies and analyses, and considered such other factors, as it deemed appropriate.

        For purposes of rendering its opinion, Goldman Sachs, with the Company's consent, relied upon and assumed the accuracy and completeness of all of the financial, legal, regulatory, tax, accounting and other information provided to, discussed with or reviewed by it, without assuming any responsibility for independent verification thereof. In that regard, Goldman Sachs assumed with the Company's consent that the Forecasts were reasonably prepared on a basis reflecting the best currently available estimates and judgments of the management of the Company. Goldman Sachs did not make an independent evaluation or appraisal of the assets and liabilities (including any contingent, derivative or other off-balance-sheet assets and liabilities) of the Company or any of its subsidiaries, and it was not furnished with any such evaluation or appraisal. Goldman Sachs assumed that all governmental, regulatory or other consents and approvals necessary for the consummation of the merger will be obtained without any adverse effect on the expected benefits of the merger in any way meaningful to its analysis. Goldman Sachs has also assumed that the merger will be consummated on the terms set forth in the merger agreement, without the waiver or modification of any term or condition the effect of which would be in any way meaningful to its analysis.

        Goldman Sachs' opinion does not address the underlying business decision of the Company to engage in the merger or the relative merits of the merger as compared to any strategic alternatives that may be available to the Company; nor does it address any legal, regulatory, tax or accounting matters. Goldman Sachs' opinion addresses only the fairness from a financial point of view, as of the date of the opinion, of $20.00 in cash per share of Company common stock to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement. Goldman Sachs' opinion does not express any view on, and does not address, any other term or aspect of the merger agreement or the merger or any term or aspect of any other agreement or instrument

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contemplated by the merger agreement or entered into or amended in connection with the merger, including the fairness of the merger to, or any consideration received in connection therewith by, the holders of any other class of securities, creditors or other constituencies of the Company; nor as to the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of the Company, or class of such persons, in connection with the merger, whether relative to the $20.00 in cash per share of Company common stock to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement or otherwise. Goldman Sachs does not express any opinion as to the impact of the merger on the solvency or viability of the Company or Virtu or the ability of the Company or Virtu to pay their respective obligations when they come due. Goldman Sachs' opinion was necessarily based on economic, monetary, market and other conditions, as in effect on, and the information made available to it as of, the date of the opinion and Goldman Sachs assumed no responsibility for updating, revising or reaffirming its opinion based on circumstances, developments or events occurring after the date of its opinion. Goldman Sachs' opinion was approved by a fairness committee of Goldman Sachs.

        The following is a summary of the material financial analyses delivered by Goldman Sachs to the Company board in connection with rendering the opinion described above. The following summary, however, does not purport to be a complete description of the financial analyses performed by Goldman Sachs, nor does the order of analyses described represent relative importance or weight given to those analyses by Goldman Sachs. Some of the summaries of the financial analyses include information presented in tabular format. The tables must be read together with the full text of each summary and are alone not a complete description of Goldman Sachs' financial analyses. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before April 17, 2017, the third trading day before the Company's and Virtu's public announcement of the merger agreement, and is not necessarily indicative of current market conditions.

        Illustrative Present Value of Future Share Price Analysis.    Goldman Sachs performed an illustrative analysis of the implied present value of the Company's future value per share of Company common stock, which is designed to provide an indication of the present value of a theoretical future value of a company's equity as a function of such company's estimated future earnings and its assumed price to future earnings per share multiple. For this analysis, Goldman Sachs used the Forecasts for each of the fiscal years 2019 to 2021. Goldman Sachs first calculated the implied values per share of Company common stock as of fiscal year-end for each of the fiscal years 2017 to 2019, by applying price to two-year forward earnings per share multiples of 8.0x to 12.0x earnings per share of Company common stock estimates for each of the fiscal years 2019 to 2021, and then discounted back to March 31, 2017, using an illustrative discount rate of 12.2%, reflecting an estimate of the Company's cost of equity (derived by utilizing the Capital Asset Pricing Model, which requires certain company-specific inputs, including a beta for the Company, which Goldman Sachs derived by reviewing the historical beta of the Company and selected companies which exhibited similar business characteristics to the Company, as well as certain financial metrics for the United States financial markets generally). These illustrative two-year forward earnings per share multiples were derived by Goldman Sachs utilizing its experience and professional judgment, taking into account current and historical trading data, the undisturbed trading price per share of Company common stock on March 14, 2017, $13.73, and adjusted analyst consensus two-year forward earnings per share as of March 14, 2017 normalized for non-recurring depreciation and amortization (as provided by the Company). This analysis resulted in a range of implied present values of $16.45 to $31.17 per share of Company common stock.

        Illustrative Discounted Cash Flow Analysis.    Using the Forecasts, Goldman Sachs performed an illustrative discounted cash flow analysis on the Company. Using discount rates ranging from 9.0% to 11.0%, reflecting estimates of the Company's weighted average cost of capital (derived by utilizing the Capital Asset Pricing Model, which requires certain company-specific inputs, including the Company's

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target capital structure weightings, the pre-tax cost of debt, after-tax cost of debt, marginal tax rate and a beta for the Company, which beta Goldman Sachs derived by reviewing the historical beta of the Company and selected companies which exhibited similar business characteristics to the Company, as well as certain financial metrics for the United States financial markets generally), Goldman Sachs discounted to present value as of March 31, 2017 (i) estimates of unlevered free cash flow for the Company for the last nine months of 2017 and for the years 2018 through 2021 as reflected in the Forecasts and (ii) a range of illustrative terminal values for the Company, which were calculated by applying perpetuity growth rates ranging from (2.0)% to 2.0%, to a terminal year estimate of the free cash flow to be generated by the Company, as reflected in the Forecasts. The range of perpetuity growth rates was estimated by Goldman Sachs utilizing its professional judgment and experience, taking into account the Forecasts, the Company's historical and market expectations regarding long-term real growth of gross domestic product and inflation. Applying the range of growth rates and discount rates referenced above to the Company's future unlevered cash flow forecasts implied a range of EBITDA (as defined below) multiples of 3.5x to 6.7x. Goldman Sachs derived ranges of illustrative enterprise values for the Company by adding the ranges of present values it derived above. Goldman Sachs then subtracted, from the range of illustrative enterprise values it derived for the Company, the amount of the Company's estimated net debt exclusive of restricted cash as of March 31, 2017 of $323 million (as provided by the Company), as provided by management of the Company, to derive a range of illustrative equity values for the Company. Goldman Sachs then divided the range of illustrative equity values it derived by the number of fully diluted outstanding shares of the Company, as provided by management of the Company, to derive a range of illustrative present values per share ranging from $15.94 to $27.09.

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        Selected Transactions Analysis.    Goldman Sachs analyzed certain information relating to the following selected transactions in the electronic trading industry since May 2011:

        While none of the target companies that participated in the selected transactions are directly comparable to the Company, the target companies that participated in the selected transactions are companies with operations that, for the purposes of analysis, may be considered similar to certain of the Company's results, market size and product profile. For the only selected transaction for which detailed financial information was publicly available, the Knight Capital Group, Inc. / GETCO Holding Company, LLC transaction, Goldman Sachs calculated and compared Enterprise Value, or EV (as defined below) as a multiple of the estimated earnings before interest, taxes, depreciation and amortization, or EBITDA (as defined below), using publicly available Wall Street research, for the year in which the transaction occurred, resulting in an EV / EBITDA multiple of 7.2x. Goldman Sachs identified an illustrative range of EV / EBITDA multiples of 6.0x - 10.0x and applied that range of illustrative multiples to the Company's estimated 2017 adjusted EBITDA, as reflected in the Forecasts, which resulted in a range of illustrative prices per share of Company common stock of $12.17 to $23.49.

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        Transaction Premia Analysis.    Using publicly available information, Goldman Sachs reviewed and analyzed average and median premia for each calendar year, for publicly disclosed all-cash acquisitions from January 1, 2012 through December 31, 2016 that resulted in a sale of control of a U.S. target company and had a transaction value greater than $250 million. Goldman Sachs calculated, for each year during this 2012 through 2016 period, the premia represented by the prices per share paid in these transactions relative to the targets' closing share prices (i) one day and (ii) one week prior to announcement. Using such data, Goldman Sachs calculated the ranges of average and median acquisition premia for each year for these transactions as 31% to 43% and 27% to 34%, respectively, for these one-day premia and 33% to 46% and 29% to 37%, respectively, for these one-week premia. Goldman Sachs then applied an illustrative range of acquisition premia of 25% to 45% to $13.73, the undisturbed trading price per share of Company common stock, to derive a range of illustrative implied prices per share of Company common stock of $17.16 to $19.91.

        Reference Information:    For reference purposes, Goldman Sachs performed additional analyses, which are summarized below.

        Selected Companies Analysis.    Goldman Sachs reviewed and compared certain financial information for the Company to corresponding financial information, ratios and public market multiples for the following publicly traded corporations in the electronic trading industry (collectively referred to as the selected companies):

        Core Peers

•

Virtu Financial, Inc.



•

Flow Traders N.V.

        Other Trading Peers

•

NEX Group plc



•

INTL FCStone Inc.



•

Investment Technology Group, Inc.

        Selected Exchanges

•

CME Group Inc.



•

Intercontinental Exchange, Inc.



•

Deutsche Börse Group



•

London Stock Exchange Group



•

Nasdaq, Inc.



•

CBOE Holdings, Inc.

Although none of the selected companies is directly comparable to the Company, the companies included were chosen because they are publicly traded companies with operations that for purposes of analysis may be considered similar to certain operations of the Company.

        Goldman Sachs calculated and compared various financial multiples and ratios using information it obtained from SEC filings, estimates from the Institutional Brokers' Estimate System, which we refer to as "IBES estimates" (as well as estimates from the Forecasts in the case of the Company), and market

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data as of April 17, 2017. With respect to its analysis, Goldman Sachs calculated for the Company and the selected companies:

•

Enterprise Value (which is defined as the equity value, calculated using the number of fully diluted shares of Company common stock, as provided by management of the Company and calculated using the treasury method, plus total debt, less total unrestricted cash and cash equivalents), which we refer to as "EV", as a multiple of estimated earnings before interest, taxes, depreciation and amortization, which we refer to as "EBITDA", for the years ended December 31, 2017 and December 31, 2018, which are referred to below as "2017 EV/EBITDA" and "2018 EV/EBITDA", respectively; and



•

Closing price per share, as of April 17, 2017, in the case of the selected companies, and, for the Company, as of such date and as of the date of the undisturbed trading price per share of Company common stock on March 14, 2017, $13.73, as a multiple of estimated GAAP earnings per share for the year ended December 31, 2017 and December 31, 2018, which is referred to below as "2017 GAAP P/E" and "2018 GAAP P/E", respectively. The results of these analyses are summarized as follows:

        Goldman Sachs then applied an illustrative range of multiples of 9.6x to 14.4x, representing a 20% discount and premium to the Core Peer median multiple of 2018 GAAP P/E, to the 2018 estimated earnings per share of Company common stock reflected in the Forecasts to obtain a range of implied values per share of $17.40 to $26.10.

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        Present Value of Price / Book Multiple to RoE Regression Analysis.    Goldman Sachs performed a regression analysis using the price / book value multiples, which we refer to as "P/B" for the following publicly traded companies (collectively referred to as the selected RoE companies) compared to the estimated 2018 return on equity, which we refer to as the "2018E RoE", for the selected RoE companies using the median estimates for such companies published by IBES as of April 17, 2017, to derive a regression line reflecting the range of P/B value multiples at a range of 2018E RoEs for the selected companies:

•

BGC Partners, Inc.



•

Flow Traders N.V.



•

The Goldman Sachs Group, Inc.



•

INTL FCStone Inc.



•

Investment Technology Group, Inc.



•

Morgan Stanley



•

Piper Jaffray Companies



•

Raymond James Financial, Inc.



•

Stifel Financial Corp.



•

Virtu Financial, Inc.

Although none of the selected RoE companies is directly comparable to the Company, the companies included were chosen because they are publicly traded companies with operations that for purposes of analysis may be considered similar to certain operations of the Company.

        The 2018E adjusted RoE for the Company on a stand-alone basis, as reflected in the Forecasts, corresponded to a P/B value per share multiple of 1.09x on the regression line. By applying P/B value per share multiples ranging from 0.84x to 1.34x, reflecting P/B value multiples of 0.25x below and above the per share multiple of 1.09x on the regression line, to the adjusted book value of the Company, adjusted for one-time charges (taxed at a rate of 38%) and the return of $400,000,000 of capital as reflected in the Forecasts, Goldman Sachs derived implied values per share of Company common stock on a stand-alone basis ranging from $16.91 to $23.41.

        The preparation of a fairness opinion is a complex process and is not necessarily susceptible to partial analysis or summary description. Selecting portions of the analyses or of the summary set forth above, without considering the analyses as a whole, could create an incomplete view of the processes underlying Goldman Sachs' opinion. In arriving at its fairness determination, Goldman Sachs considered the results of all of its analyses and did not attribute any particular weight to any factor or analysis considered by it. Rather, Goldman Sachs made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of its analyses. No company or transaction used in the above analyses as a comparison is directly comparable to the Company or the contemplated merger.

        Goldman Sachs prepared these analyses for purposes of Goldman Sachs' providing its opinion to the Company board as to the fairness from a financial point of view of the $20.00 in cash per share of Company common stock to be paid to the holders (other than Virtu and its affiliates) of shares of Company common stock pursuant to the merger agreement. These analyses do not purport to be appraisals nor do they necessarily reflect the prices at which businesses or securities actually may be sold. Analyses based upon forecasts of future results are not necessarily indicative of actual future results, which may be significantly more or less favorable than suggested by these analyses. Because these analyses are inherently subject to uncertainty, being based upon numerous factors or events

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beyond the control of the parties or their respective advisors, none of the Company, Goldman Sachs or any other person assumes responsibility if future results are materially different from those forecast.

        The $20.00 per share merger consideration was determined through arm's-length negotiations between the Company and Virtu and was approved by the Company board. Goldman Sachs provided advice to the Company during these negotiations. Goldman Sachs did not, however, recommend any specific amount of consideration to the Company or the Company board or that any specific amount of consideration constituted the only appropriate consideration for the merger.

        As described above, Goldman Sachs' opinion to the Company board was one of many factors taken into consideration by the Company board in making its determination to approve the merger agreement. The foregoing summary does not purport to be a complete description of the analyses performed by Goldman Sachs in connection with the fairness opinion and is qualified in its entirety by reference to the written opinion of Goldman Sachs attached as Annex C.

        Goldman Sachs and its affiliates are engaged in advisory, underwriting and financing, principal investing, sales and trading, research, investment management and other financial and non-financial activities and services for various persons and entities. Goldman Sachs and its affiliates and employees, and funds or other entities in which they invest or with which they co-invest, may at any time purchase, sell, hold or vote long or short positions and investments in securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments of the Company, Virtu, any of their respective affiliates and third parties, including Leucadia National Corporation, the parent of Jefferies, Temasek Holdings (Private) Limited, an affiliate of a significant shareholder of Virtu ("Temasek"), the Republic of Singapore and its agencies or instrumentalities (collectively, the "Republic of Singapore"), including the Singapore Minister for Finance, the sole shareholder of Temasek, North Island Holdings I, L.P. ("North Island"), which, together with certain of its affiliates, is providing equity financing to Virtu in connection with the merger, GIC Private Limited ("GIC"), which is providing equity financing to North Island in connection with the merger, the Public Sector Pension Investment Board ("PSP"), which is providing equity financing to North Island in connection with the merger, and any of their respective affiliates and portfolio companies, or any currency or commodity that may be involved in the merger for the accounts of Goldman Sachs and its affiliates and employees and their customers.

        Goldman Sachs acted as financial advisor to the Company in connection with, and participated in certain of the negotiations leading to, the merger. Goldman Sachs has provided certain investment banking services to the Company and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation. During the two year period ended April 20, 2017, the Investment Banking Division of Goldman Sachs has not been engaged by the Company and/or its affiliates to provide financial advisory and/or underwriting services for which Goldman Sachs has received compensation.

        Goldman Sachs has provided certain investment banking services to Virtu and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation, including having acted as lead bookrunner with respect to an initial public offering of 19,012,112 shares of Class A common stock of Virtu in April 2015, and as the sole bookrunner with respect to a secondary public offering of 6,473,371 shares of Class A common stock of Virtu in November 2015. During the two-year period ended April 20, 2017, Goldman Sachs has received compensation for financial advisory and/or underwriting services provided by its Investment Banking Division to Virtu and/or its affiliates of approximately $9,500,000.

        Robert Zoellick, previously Chairman of Goldman Sachs Regional Advisors and an advisor to Goldman Sachs Asset Management, is a board member of Temasek. Mr. Zoellick no longer serves in either of these roles at Goldman Sachs as of the end of 2016, and was officially separated from Goldman Sachs as of March 31, 2017. Goldman Sachs also has provided certain investment banking services to Temasek and/or its affiliates from time to time for which the Investment Banking Division of

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Goldman Sachs has received, and may receive, compensation, including having acted as joint bookrunner with respect to a secondary public offering of 26,311,309 common shares of Markit Limited, a portfolio company of Temasek, in June 2015; as joint bookrunner with respect to a secondary public offering of 15,000,000 ordinary shares of Evonik Industries AG, a portfolio company of Temasek, in July 2015; as sole bookrunner with respect to a secondary public offering of 20,943,741 shares of common stock of Univar Inc., a portfolio company of Temasek, in August 2016; and as bookrunner with respect to a bank loan (aggregate principal amount of $2,600,000,000) to Level Communications Inc., a portfolio company of Temasek, in February 2017. During the two-year period ended April 20, 2017, Goldman Sachs has received compensation for financial advisory and/or underwriting services provided by its Investment Banking Division directly to Temasek and/or to its affiliates and portfolio companies (which may include companies that are not controlled by Temasek) of approximately $5,000,000. Goldman Sachs also has provided certain investment banking services to Republic of Singapore and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation.

        During the two year period ended April 20, 2017, the Investment Banking Division of Goldman Sachs has not been engaged by North Island or its affiliates and portfolio companies (which may include companies that are not controlled by North Island) to provide financial advisory or underwriting services for which Goldman Sachs has received compensation.

        Goldman Sachs also has provided certain investment banking services to GIC and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation, including having acted as financial advisor to GIC with respect to GIC's sale of its stake in Associated British Ports in July 2015; as financial advisor to TDR Capital LLP, a portfolio company of GIC, with respect to its acquisition of LeasePlan, in March 2016; as bookrunner with respect to a bridge loan (aggregate principal amount of $1,784,510,000) to TDR Capital LLP, a portfolio company of GIC, in March 2016; as bookrunner with respect to a bank loan (aggregate principal amount of $1,900,000,000) to Ancestry.com Inc., a portfolio company of GIC, in October 2016; as bookrunner with respect to a public offering by Multiplan, a portfolio company of GIC, of its 7.125% Senior Unsecured Notes due 2024 (aggregate principal amount of $460,000,000) in November 2016; and as bookrunner with respect to a bank loan (aggregate principal amount of €1,600,000,000) to Eircom Group PLC, a portfolio company of GIC, in March 2017. During the two year period ended April 20, 2017, Goldman Sachs has received compensation for financial advisory and/or underwriting services provided by its Investment Banking Division directly to GIC and/or to its affiliates and portfolio companies (which may include companies that are not controlled by GIC) of approximately $50,700,000.

        Goldman Sachs also has provided certain investment banking services to PSP and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation, including having acted as arranger with respect to a bank loan (aggregate principal amount of $2,430,000,000) to Telesat Canada, a portfolio company of PSP, in November 2016; as bookrunner with respect to a public offering by Telesat Canada, a portfolio company of PSP, of its 8.875% Notes due 2024 (aggregate principal amount of $500,000,000) in November 2016; as financial advisor to Acelity, a portfolio company of PSP, with respect to the sale of LifeCell, in January 2017; as bookrunner with respect to a bank loan (aggregate principal amount of $1,200,000,000) to American Wholesale Insurance Group Inc., a portfolio company of PSP, in January 2017; as bookrunner with respect to a bank loan (aggregate principal amount of $1,350,000,000) to Investcorp International Inc., a portfolio company of PSP, in March 2017; and as bookrunner with respect to a bank loan (aggregate principal amount of $1,340,000,000) to Acelity, a portfolio company of PSP, in February 2017. During the two year period ended April 20, 2017, Goldman Sachs has received compensation for financial advisory and/or underwriting services provided by its Investment Banking Division directly to PSP

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and/or to its affiliates and portfolio companies (which may include companies that are not controlled by PSP) of approximately $27,000,000.

        Goldman Sachs may also in the future provide investment banking services to the Company, Virtu, Jefferies, Temasek, the Republic of Singapore, North Island, GIC and PSP and their respective affiliates and, in the case of Jefferies, Temasek, North Island, GIC and PSP, portfolio companies for which the Investment Banking Division of Goldman Sachs may receive compensation. Affiliates of Goldman Sachs also may have co-invested with Jefferies, Temasek, North Island, GIC, PSP and their respective affiliates from time to time and may have invested in limited partnership units of affiliates of Jefferies, Temasek, North Island GIC or PSP from time to time and may do so in the future.

        The Company board selected Goldman Sachs as its financial advisor because it is an internationally recognized investment banking firm that has substantial experience in transactions similar to the merger. Pursuant to a letter agreement dated April 11, 2017, the Company engaged Goldman Sachs to act as its financial advisor in connection with the contemplated merger. The engagement letter between the Company and Goldman Sachs provides for a transaction fee of $15,000,000, $4,000,000 of which Goldman Sachs became entitled to receive upon the execution of the engagement letter between the Company and Goldman Sachs and the remainder of which is contingent upon consummation of the merger. If the merger is not consummated, Goldman Sachs may be entitled to receive an advisory fee of $10,000,000 in connection with its advice relating to other strategic alternatives that may be pursued by the Company, $4,000,000 of which Goldman Sachs became entitled to receive upon the execution of the engagement letter between the Company and Goldman Sachs. In addition, the Company has agreed to reimburse Goldman Sachs for certain of its expenses, including attorneys' fees and disbursements, and to indemnify Goldman Sachs and related persons against various liabilities, including certain liabilities under the federal securities laws.

Financing of the Merger

        Virtu intends to finance the merger consideration with a combination of equity and debt financing (the sources of which we refer to as the "financing sources"). On April 20, 2017, in connection with the entry into the merger agreement by Virtu and the Company, Virtu entered into an investment agreement with North Island, an investment vehicle funded by GIC, a sovereign wealth fund of Singapore, PSP, one of Canada's largest pension investment managers, and certain individuals, pursuant to which North Island committed to purchase 40,064,103 shares of Virtu Class A common stock for approximately $625 million (which we refer to as the "NI investment"). At the same time, Virtu entered into an investment agreement with Aranda Investments Pte. Ltd, an investment vehicle funded by Temasek, an investment company based in Singapore, pursuant to which Aranda Investments Pte. Ltd committed to purchase 8,012,821 shares of Virtu Class A common stock for approximately $125 million (which we refer to as the "Temasek investment", and which, together with the NI investment, we collectively refer to as the "equity financing"). The sale of shares is conditioned upon, among other things, the closing of the merger. Virtu also entered into a commitment with J.P. Morgan Chase Bank, N.A. to provide up to $1.65 billion of debt financing for the transaction.

        Pursuant to the merger agreement, Virtu is required to use its reasonable best efforts to consummate the equity financing and the debt financing. Further, in the event that any portion of the equity financing or the debt financing becomes unavailable, Virtu is required to use its reasonable best efforts to obtain as promptly as practicable alternate equity financing or debt financing, as the case may be, on terms not materially less favorable to Virtu.

        The obligations of Virtu and Merger Sub to complete the merger are not contingent upon the receipt of the financing.

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Interests of Certain Persons in the Merger

        In considering the recommendation of the Company board with respect to the merger, you should be aware that the Company's directors and executive officers have certain interests in the merger that may be different from, or in addition to, the interests of the other Company stockholders. The Company board was aware of and considered these interests, among other matters, in evaluating and negotiating the merger agreement and the merger, and in determining to recommend to Company common stockholders that they vote for the merger proposal and thereby approve the transactions contemplated by the merger agreement, including the merger. These interests are described below.

        The initial written proposal to acquire the Company presented by Virtu did not provide for any continuing role at the combined company for the Company's directors or executive officers. No such roles have been discussed subsequently between the Company and Virtu.

Treatment of Company Equity Awards and Company Warrants

        The stock options, SARs and RSUs (which we collectively refer to as the "Company equity awards") held by the Company's directors and executive officers immediately prior to the effective time will be cancelled in exchange for a cash payment in the same manner as those Company equity awards held by other employees of the Company. Company warrants held by the Company's directors and executive officers immediately prior to the effective time will be converted into the right to receive a cash payment upon exercise in the same manner as the other outstanding Company warrants. As described further in the sections titled "The Merger Agreement—Treatment of Company Equity Awards" and "The Merger Agreement—Treatment of Company Warrants", such awards and warrants will be subject to the following treatment:

•

Stock Options:  At the effective time, each outstanding stock option granted under the Company stock plan will be cancelled and converted automatically into the right to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to the stock option immediately prior to the effective time and (y) the excess, if any, of the merger consideration of $20.00 per share over the exercise price per share of such stock option, less applicable taxes required to be withheld with respect to such payment. Any stock option that has an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share will be cancelled at the effective time for no consideration or payment.



•

SARs:  At the effective time, each outstanding SAR granted under the Company stock plan will automatically and without any required action on the part of the holder thereof, be cancelled and will entitle the holder of such SAR to receive an amount in cash equal to the product of (i) the number of shares of Company common stock subject to such SAR immediately prior to the effective time and (ii) the excess, if any, of (x) the merger consideration of $20.00 per share over (y) the exercise price per share of such SAR, less applicable taxes required to be withheld with respect to such payment. Because all outstanding SARs have an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share, all SARs will be cancelled at the effective time for no consideration or payment.



•

RSUs:  At the effective time, each outstanding RSU under the Company stock plan will be cancelled and converted automatically into the right to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to such RSU immediately prior to the effective time and (y) the merger consideration of $20.00 per share, less applicable taxes required to be withheld with respect to such payment.



•

Warrants:  At the effective time, each outstanding warrant to purchase shares of the Company common stock issued and outstanding immediately prior to the effective time of the merger will be converted into the right to receive an amount in cash equal to the product of (x) the number

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of shares of Company common stock subject to the Company warrant immediately prior to the effective time and (y) the excess, if any, of the merger consideration of $20.00 per share over the then-current exercise price per share of Company common stock (without giving effect to any of the transactions contemplated by the merger agreement) previously subject to such Company warrant, less applicable taxes required to be withheld with respect to such payment.

        The following table sets forth for (i) each named executive officer, (ii) the three other executive officers (as a group) and (iii) the twelve non-employee directors (as a group), the number of RSUs and stock options held by such executive officer or group of non-employee directors, as applicable, and the cash amounts payable (on a pre-tax basis) in respect thereof, assuming solely for this purpose that the completion of the merger occurs on May 24, 2017. The amounts reflected in the table below are based on the number of equity awards held by the executive officers and non-employee directors as of May 24, 2017 and depending on when the merger occurs, certain Company equity awards that are unvested as of the date hereof and included in the table below may vest pursuant to their terms, independent of the merger.

Employment Arrangements with Executive Officers

        Messrs. Coleman, Parratt, Primmer, Tusar, Blum, McCarthy and Ogurtsov.    Each of Messrs. Coleman, Parratt, Primmer, Tusar, Blum, McCarthy and Ogurtsov is party to an employment agreement with the Company (each, an "employment agreement" and collectively, the "employment agreements"). Under their employment agreements, each of these executive officers will be entitled to certain severance payments and benefits if (a) his employment is terminated without "cause" or (b) he terminates his employment for "good reason" (each as defined in the employment agreements). We use the term "qualifying termination" to refer to both a termination by the Company without cause and a resignation by the executive for good reason.

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        Each employment agreement provides that in the event of a qualifying termination the executive officer will be entitled to receive:

•

non-competition payments equal to 100% (200% for Mr. Coleman) of the executive officer's base salary; provided that for Mr. Tusar, the non-competition payment is 50% of an amount equal to (a) his base salary plus (b) 75% of the cash portion of the annual incentive award paid in respect of the fiscal year preceding the year in which the qualifying termination occurs. For each executive, the non-competition payments are paid in equal monthly installments over a period of six months following the qualifying termination, subject to such executive's ongoing compliance with non-competition restrictions over the same period (12 months for Mr. Coleman) and non-solicitation restrictions for a period of 18 months, provided that all non-solicitation and non-competition restrictions are reduced to a six-month period following a qualifying termination; and



•

payment of COBRA health insurance premiums for up to 12 months following the qualifying termination.

        The executive officers are required to execute an effective and enforceable general release of all claims against the Company as a condition to receiving the payments and benefits outlined above, and such benefits shall be reduced to give the best net-after-tax benefit to the executive in the case excise taxes are imposed under Section 280G of the Code if any payments under the employment or otherwise payable in connection with the transaction would be deemed to be "excess parachute payments."

        Mr. Allison.    Pursuant to his employment agreement with the Company, the Company is required to give Mr. Allison six months' written notice to terminate his employment, provided that the Company may, at its discretion, terminate Mr. Allison's employment with immediate effect and pay Mr. Allison's base salary over the six-month period instead of giving advance notice of such termination. Mr. Allison's employment agreement requires that he comply with non-competition and non-solicitation covenants for a period of 12 months following the termination of his employment.

2017 Fiscal Year Bonus

        In connection with negotiating the merger agreement, the parties agreed that each executive officer would be eligible to earn a bonus for the 2017 fiscal year in an amount determined by the Chief Executive Officer of the Company. Upon a qualifying termination following the completion of the merger, each executive officer will be paid his 2017 bonus, provided, that payment of such amount shall be subject to the executive's delivery (and non-revocation) of a general release of claims and covenant not to sue in favor of Virtu, the Company and their respective subsidiaries.

        For an estimate of the value of the payments and benefits described above that would be payable to the Company's named executive officers upon a qualifying termination, see "Advisory Vote on Merger-Related Compensation for the Company's Named Executive Officers—Golden Parachute Compensation," below.

Indemnification; Directors' and Officers' Insurance

        The merger agreement provides that all rights, existing as of the date of the merger agreement, to indemnification, advancement of expenses and exculpation from liabilities for acts or omissions occurring at or prior to the completion of the merger in favor of the current or former officers, directors or employees of the Company or any of its subsidiaries will continue in full force and effect. The merger agreement also provides that, following completion of the merger, the surviving corporation will indemnify and hold harmless, to the fullest extent permitted by applicable law, all individuals who are, as of the date of the merger agreement and at any time from and after the date of

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the merger agreement until the completion of the merger, directors or officers of the Company and its subsidiaries (in their capacity as such), against any costs, claims, expenses and liabilities, whether arising before or after the effective time, arising out of the fact that such person is or was a director or officer of the Company or its subsidiaries, and pertaining to matters existing or occurring at or prior to the effective time, and will also advance expenses to such persons, provided that such person provides an undertaking to repay such advances if it is ultimately determined that such person is not entitled to indemnification.

        Subject to certain limitations, the merger agreement also requires the surviving corporation to maintain, for a period of six years after the completion of the merger, the Company's existing directors' and officers' liability insurance policy, or policies with a substantially comparable insurer of at least the same coverage and amounts and containing terms and conditions that are no less advantageous to the insured, with respect to claims against present and former officers and directors of the Company and its subsidiaries arising from facts or events that occurred at or prior to the effective time. The surviving corporation will not, however, be required to spend annually in the aggregate an amount in excess of 300% of the annual premium paid by the Company for the year ended December 31, 2016 under its current policy. In lieu of the foregoing, at the request of Virtu, the Company may obtain at or prior to the effective time a six-year prepaid "tail" policy under the Company's existing directors' and officers' insurance policy providing coverage equivalent to the current policies of directors' and officers' liability insurance maintained by the Company as of the date of the merger agreement. For additional information, see the section entitled "The Merger Agreement—Covenants and Agreements—Director and Officer Indemnification and Insurance" of this proxy statement.

Material U.S. Federal Income Tax Consequences of the Merger

        The following is a summary of the material U.S. federal income tax consequences of the merger to U.S. holders (as defined below) whose shares of Company common stock are converted into the right to receive cash in the merger. This summary does not purport to consider all aspects of U.S. federal income taxation that might be relevant to Company stockholders. This discussion does not address the consequences of the merger to holders who receive cash pursuant to the exercise of appraisal rights. This discussion applies to you only if you hold shares of Company common stock as capital assets for U.S. federal income tax purposes, and does not apply to you if you are a member of a special class of holders subject to special rules, including but not limited to:

•

Company common stockholders that are not U.S. holders;



•

Dealers in securities;



•

Traders in securities that elect to use a mark-to-market method of accounting for securities holdings;



•

Tax-exempt organizations;



•

Life insurance companies;



•

Financial institutions;



•

Regulated investment companies;



•

Real estate investment trusts;



•

Persons that use shares of Company common stock as part of a straddle or a hedging or conversion transaction;



•

Persons that have a functional currency other than the U.S. dollar;

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•

Persons that acquired shares of Company common stock upon the exercise of stock options or otherwise as compensation; or



•

Stockholders who hold an equity interest, actually or constructively, in Virtu.

        This discussion is based on the Internal Revenue Code of 1986, as amended (which we refer to as the "Code"), its legislative history, existing and proposed regulations promulgated thereunder, published rulings, administrative guidance from the Internal Revenue Service (which we refer to as the "IRS") and court decisions, all as of the date of this proxy statement. These laws and other authorities are subject to change, possibly on a retroactive basis.

        This discussion addresses only U.S. federal income taxation. This discussion does not address any tax consequences arising under the unearned income Medicare contribution tax pursuant to the Health Care and Education Reconciliation Act of 2010, nor does it address any aspect of foreign, state, local, alternative minimum, estate, gift or other tax law that may be applicable to a holder.

        This discussion is intended to provide only a general summary of the material U.S. federal income tax consequences of the merger to U.S. holders of shares of Company common stock. The Company does not intend for this discussion to be a complete analysis or description of all potential U.S. federal income tax consequences of the merger. The U.S. federal income tax laws are complex and subject to varying interpretations. Accordingly, the IRS may not agree with the tax consequences described in this proxy statement.

        If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds Company common stock, the tax treatment of a partner generally will depend on the status of the partner and the activities of the partner and the partnership. A partner of a partnership holding Company common stock should consult the partner's tax advisor regarding the U.S. federal income tax consequences of the merger to such partner.

        Stockholders are urged to consult with their own tax advisors as to the tax consequences of the merger in their particular circumstances, including the applicability and effect of U.S. federal (including the alternative minimum tax), state, local or non-U.S. and other tax laws and of changes in those laws.

        For purposes of this discussion, we use the term "U.S. holder" to mean a beneficial owner of shares of Company common stock that is, for U.S. federal income tax purposes:

•

An individual who is a citizen or resident of the United States;



•

A corporation (or other entity taxable as a corporation for U.S. federal income tax purposes) created or organized under the laws of the United States or any of its political subdivisions;



•

A trust that (i) is subject to the supervision of a court within the United States and the control of one or more U.S. persons or (ii) has a valid election in effect under applicable U.S. Treasury Regulations to be treated as a U.S. person; or



•

An estate that is subject to U.S. federal income tax on the estate's income regardless of its source.

Tax Consequences of the Merger

        The exchange of shares of Company common stock for cash in the merger generally will be a taxable transaction for U.S. federal income tax purposes. In general, a U.S. holder whose shares of Company common stock are converted into the right to receive cash in the merger will recognize capital gain or loss for U.S. federal income tax purposes equal to the difference, if any, between (i) the amount of cash received with respect to such shares (determined before the deduction of any applicable withholding taxes, as described below under "—Backup Withholding and Information

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Reporting"), and (ii) the U.S. holder's adjusted tax basis in such shares. A U.S. holder's adjusted tax basis will generally equal the price the U.S. holder paid for such shares. Gain or loss will be determined separately for each block of shares of Company common stock (i.e., shares acquired at the same cost in a single transaction). Such capital gain or loss will be long-term capital gain or loss, provided that the U.S. holder's holding period for each such block of shares of Company common stock exceeds one year at the effective time. Long-term capital gains of non-corporate U.S. holders are generally eligible for a reduced rate of U.S. federal income taxation. There are limitations on the deductibility of capital losses.

Backup Withholding and Information Reporting

        A U.S. holder may, under certain circumstances, be subject to information reporting and backup withholding (at a rate of 28%) with respect to the merger consideration, unless such holder properly establishes an exemption or provides its correct tax identification number and otherwise complies with the applicable requirements of the backup withholding rules.

        Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules can be refunded or credited against a payee's U.S. federal income tax liability, if any, provided that such U.S. holder furnishes the required information to the IRS in a timely manner.

        The U.S. federal income tax consequences described above are not intended to constitute a complete description of all tax consequences relating to the merger. Because individual circumstances may differ, each stockholder should consult the stockholder's tax advisor regarding the applicability of the rules discussed above to the stockholder and the particular tax effects to the stockholder of the merger in light of such stockholder's particular circumstances and the application of state, local and foreign tax laws.

Regulatory Approvals Required for the Merger

        To complete the merger, the parties must make regulatory filings and obtain authorizations, approvals or consents necessary to obtain the required governmental approvals. Under the terms of the merger agreement, the merger cannot be completed until any waiting periods applicable to the consummation of the merger under the HSR Act have expired or been terminated. On April 28, 2017, Virtu and the Company filed notification of the proposed merger with the U.S. Federal Trade Commission (which we refer to as the "FTC") and the Department of Justice (which we refer to as the "DOJ") under the HSR Act.

        On May 30, 2017, the FTC notified the Company that it had terminated the waiting period under the HSR Act effective as of May 30.

        At any time before or after consummation of the merger, the DOJ or the FTC (notwithstanding the termination of the waiting period under the HSR Act) could take such action under antitrust laws as it deems necessary, including seeking to enjoin the completion of the merger and seeking divestiture of substantial assets of the Company or Virtu. At any time before or after the completion of the merger (and notwithstanding the termination of the waiting period under the HSR Act), any state or non-U.S. governmental entity could take such action under antitrust laws as it deems necessary. Such action could include seeking to enjoin the completion of the merger and seeking divestiture of substantial assets of the Company, Virtu or Merger Sub. Private parties may also seek to take legal action under antitrust laws under certain circumstances.

        Rule 1017 of the National Association of Securities Dealers (which we refer to as the "NASD"), which is administered by the NASD's successor, FINRA, provides that a FINRA member entity must file an application for approval of a change in the equity ownership of the member that results in one person or entity directly or indirectly owning or controlling 25% or more of the equity capital of such

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member at least 30 days prior to such change. KCG Americas LLC, a subsidiary of the Company and a FINRA member entity, submitted an application to FINRA on April 21, 2017 requesting approval of a change in control in connection with the merger.

        In addition, certain non-U.S. subsidiaries of the Company must make regulatory filings and obtain authorizations, approvals or consents from the FCA and from the FSA. The Company and Virtu made the required filings with the FCA and the FSA on May 5, 2017.

        There can be no assurance that all of the required governmental approvals, or any other regulatory approvals that might be required to consummate the merger, will be sought or obtained and, if obtained, there can be no assurance as to the timing of any approvals, ability to obtain the approvals on satisfactory terms or the absence of any litigation challenging such approvals. There can also be no assurance that the DOJ, the FTC or any other governmental entity or any private party will not attempt to challenge the merger on antitrust grounds, and, if such a challenge is made, there can be no assurance as to its result.

Litigation Related to the Merger

        Between May 19 and May 23, 2017, five putative class actions relating to the Merger were filed by shareholders of KCG against KCG and its board of directors in the United States District Court for the Southern District of New York. The cases are captioned Siegal v. KCG Holdings, Inc., et al., Case No. 1:17-cv-3886, Berg v. KCG Holdings, Inc., et al., Case No. 1:17-cv-3802, Pauza v. KCG Holdings, Inc., et al., Case No. 1:17-cv-3885, Evangelista v. KCG Holdings, Inc., et al., Case No. 1:17-cv-3959, and Klein v. KCG Holdings, Inc., et al., Case No. 1:17-cv-3946. The Klein and Berg complaints also name as defendants Virtu and Merger Sub. The complaints assert that the defendants violated Sections 14(a) and 20(a) of the Exchange Act in connection with the preliminary proxy statement filed with the SEC by KCG in connection with the Merger.

        All five complaints allege, among other things, that the individual defendants and the Company violated federal securities laws by disseminating a preliminary proxy that included allegedly material misstatements or omissions about the Merger and the sale process leading up to the Merger. Among other things, the complaints allege that the preliminary proxy omits or misrepresents material information concerning: (i) the Company management's projections that were utilized by Goldman Sachs, the Company's financial advisor in connection with the Merger, (ii) the valuation analyses prepared by Goldman Sachs in connection with the rendering of its fairness opinion, and (iii) the sale process leading up to the Merger. The complaints seek, among other things, (i) an order preliminarily and permanently enjoining the Merger until the allegedly omitted information is disclosed, (ii) rescission of the Merger or an award of damages in the event the merger is consummated, and (iii) an award of plaintiff's attorneys' fees and costs. The defendants have not yet answered or otherwise responded to these complaints.

        On May 31, 2017, the parties to these litigations entered into a memorandum of understanding that sets forth an agreement in principle to settle and release all claims asserted by plaintiffs in the litigations. The settlement is subject to, among other things, the negotiation and execution of definitive documentation.

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THE MERGER AGREEMENT

        The following discussion contains certain information about the merger and the merger agreement. The discussion is subject, and qualified in its entirety by reference, to the merger agreement attached as Annex A to this proxy statement and incorporated herein by reference. We urge you to read carefully this entire proxy statement, including the merger agreement attached as Annex A, for a more complete understanding of the merger.

Explanatory Note Regarding the Merger Agreement

        The merger agreement and this summary of terms are included to provide you with information regarding the terms of the merger agreement. Factual disclosures about the Company and Virtu contained in this proxy statement or in the public reports of the Company and Virtu filed with the SEC may supplement, update or modify the factual disclosures about the Company and Virtu contained in the merger agreement. The merger agreement contains representations and warranties by the Company, on the one hand, and Virtu, on the other hand. The representations, warranties and covenants made in the merger agreement by the Company and Virtu were qualified and subject to important limitations that were negotiated and agreed to by the Company and Virtu. In particular, in your review of the representations and warranties contained in the merger agreement, and described in this summary, it is important to bear in mind that the representations and warranties were negotiated with the principal purposes of establishing circumstances in which a party to the merger agreement may have the right not to consummate the merger and allocating risk between the parties to the merger agreement, rather than establishing matters as facts. The representations and warranties also may be subject to a contractual standard of materiality different from that generally relevant to investors or applicable to reports and documents filed with the SEC, and some were qualified by the matters contained in confidential disclosure schedules that the Company and Virtu each delivered in connection with the merger agreement and certain documents filed with the SEC. Moreover, information concerning the subject matter of the representations and warranties, which do not purport to be accurate as of the date of this proxy statement, may have changed since the date of the merger agreement.

        For the foregoing reasons, the representations and warranties, or any descriptions of those provisions, should not be read alone or relied upon as characterizations of the actual state of facts or condition of the Company, Virtu or any of their respective subsidiaries or affiliates. Instead, such provisions or descriptions should be read only in conjunction with the other information provided elsewhere in this document or incorporated by reference into this proxy statement. See "Where You Can Find More Information." The Company will provide additional disclosures in their public reports to the extent they are aware of the existence of any material facts that are required to be disclosed under federal securities laws and that might otherwise contradict the terms and information contained in the merger agreement and will update such disclosure as required by federal securities laws.

Structure of the Merger

        Each of the Company's and Virtu's respective boards of directors has unanimously approved the merger agreement and the merger. Under the merger agreement, Merger Sub, an indirect wholly owned subsidiary of Virtu, will merge with and into the Company, so that the Company will be the surviving entity in the merger and will be an indirect wholly owned subsidiary of Virtu when the merger is completed.

Merger Consideration

        In the merger, each share of Company common stock issued and outstanding immediately prior to the effective time, except for specified shares held by the Company or owned by Virtu or Merger Sub

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and shares of Company common stock held by Company stockholders who properly exercise dissenters' rights, shall be converted into the right to receive $20.00 in cash without interest.

        At the effective time, all Company common stock will convert into the right to receive the merger consideration, will no longer be outstanding and will automatically be cancelled and will cease to exist, and will thereafter represent only the right to receive the merger consideration to be paid in accordance with the merger agreement.

        The price to be paid for each share of Company common stock in the merger will be adjusted appropriately to reflect the effect of any change in the outstanding shares of Company common stock, including if the Company pays dividends in, splits, combines into a smaller number or issues by reclassification any shares of Company common stock (or undertakes any similar act) prior to the effective time.

        At the effective time, each share of common stock of Merger Sub issued and outstanding immediately prior to the effective time will be converted into one share of common stock of the surviving corporation.

        Shares of Company common stock held by the Company as treasury stock (other than shares in a Company plan (as defined in "The Merger Agreement—Covenants and Agreements")) or owned by Virtu or Merger Sub (other than shares held in trust accounts, managed accounts, mutual funds and the like, or otherwise held in a fiduciary or agency capacity, that are beneficially owned by third parties) immediately prior to the effective time of the merger, and shares held by Company stockholders who have properly exercised appraisal rights with respect to their shares, will be cancelled, and no merger consideration will be paid with respect to those shares.

Treatment of Company Equity Awards

        Stock Options:    At the effective time, each outstanding stock option under the Company stock plan will be cancelled and will entitle the holder of such stock option to receive an amount in cash equal to the product of (i) the number of shares of Company common stock subject to such stock option immediately prior to the effective time and (ii) the excess, if any, of (x) the merger consideration of $20.00 per share over (y) the exercise price per share of such stock option, less applicable taxes required to be withheld with respect to such payment. Any stock option that has an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share will be cancelled at the effective time for no consideration or payment.

        SARs:    At the effective time, each outstanding SAR granted under the Company stock plan will be cancelled and will entitle the holder of such SAR to receive an amount in cash equal to the product of (i) the number of shares of Company common stock subject to such SAR immediately prior to the effective time and (ii) the excess of (x) the merger consideration of $20.00 per share over (y) the exercise price per share of such SAR, less applicable taxes required to be withheld with respect to such payment. Because all outstanding SARs have an exercise price per share that is greater than or equal to the merger consideration of $20.00 per share, all SARs will be cancelled at the effective time for no consideration or payment.

        RSUs:    At the effective time, any vesting conditions applicable to each outstanding RSU under the Company stock plan, whether vested or unvested, will be cancelled and will entitle the holder of such RSU to receive an amount in cash equal to the product of (x) the number of shares of Company common stock subject to such RSU immediately prior to the effective time and (y) the merger consideration of $20.00 per share, less applicable taxes required to be withheld with respect to such payment.

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Treatment of Company Warrants

        Each of the Company's Class A warrants to purchase shares of the Company common stock for a purchase price per share of $11.70, the Company's Class B warrants to purchase shares of the Company common stock for a purchase price per share of $13.16, the Company's Class C warrants to purchase shares of the Company common stock for a purchase price per share of $14.63 issued and outstanding immediately prior to the effective time of the merger will be converted into the right to receive an amount in cash equal to the product of (A) the total number of shares of Company common stock subject to such Company warrant and (B) the excess, if any, of the merger consideration over the then-current exercise price per share of Company common stock (without giving effect to any of the transactions contemplated by the merger agreement) previously subject to such Company warrant, less applicable taxes required to be withheld with respect to such payment (such amount being referred to as the "warrant consideration").

Closing and Effective Time

        The merger will be completed only if all conditions to the merger discussed in this proxy statement and set forth in the merger agreement are either satisfied or waived. See "—Conditions to Complete the Merger."

        The merger will become effective as set forth in the certificate of merger to be filed with the Secretary of State of the State of Delaware. The closing of the transactions contemplated by the merger agreement will occur on the later of (i) the fifth business day following the first day on which there is satisfaction or waiver of all of the conditions set forth in the merger agreement and (ii) the earlier of (A) a date during the marketing period selected by Virtu on one business day's notice to the Company and (B) the fifth business day following the final day of the marketing period, in each case unless changed by mutual agreement of the parties. It currently is anticipated that the completion of the merger will occur in the third quarter of 2017 subject to the receipt of stockholder and required governmental approvals and the satisfaction of other closing conditions, but neither the Company nor Virtu can guarantee when or if the merger will be completed.

        As used herein, "marketing period" means the first period of 17 consecutive business days, throughout and at the end of which Virtu has obtained all necessary information from the Company in connection with the debt financing.

Delivery of Merger Consideration

        At or promptly after the effective time, and in any event within two business days thereafter, Virtu shall deposit, or shall cause to be deposited, with a paying agent selected by Virtu and consented to by the Company (such consent not to be unreasonably withheld), for the benefit of the Company's stockholders, an amount in cash sufficient to pay the aggregate merger consideration, to be paid in exchange for outstanding shares of Company common stock.

        Pursuant to the terms of the merger agreement, the warrant consideration will be paid by the surviving corporation in accordance with the terms of the warrant agreement between the Company and Computershare Shareowner Services LLC, dated July 1, 2013 (which we refer to as the "warrant agreement").

        The conversion of Company common stock into the right to receive the merger consideration will occur automatically at the effective time. After completion of the merger, the paying agent will exchange certificates representing shares of Company common stock for the merger consideration to be received pursuant to the terms of the merger agreement.

        As soon as reasonably practicable after the completion of the merger, and in any event within five business days thereafter, the paying agent will mail to each holder of record of Company common

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stock immediately prior to the effective time a letter of transmittal and instructions on how to surrender shares of Company common stock in exchange for the merger consideration the holder is entitled to receive under the merger agreement.

        Upon surrender to the paying agent of a certificate or certificates (or affidavit of loss in lieu thereof) or transfer of uncertificated shares to the paying agent, together with a properly completed letter of transmittal, each Company stockholder eligible to receive the merger consideration will be entitled to receive the merger consideration for each share of Company common stock formerly represented by a certificate or for each uncertificated share of Company common stock.

        If a certificate for Company common stock has been lost, stolen or destroyed, the paying agent will issue the merger consideration upon receipt of an affidavit of that fact by the claimant and, if required by the surviving corporation, the posting of a bond in an amount as Virtu may direct as indemnity against any claim that may be made against it with respect to such certificate.

        After completion of the merger, there will be no further transfers on the stock transfer books of the Company of shares of Company common stock that were issued and outstanding immediately prior to the effective time. If, after the effective time, certificates or uncertificated shares are presented to the surviving corporation, they will be cancelled and exchanged for the merger consideration to be paid in consideration therefor in accordance with the procedures set forth in the merger agreement.

Appraisal Rights

        If required by the DGCL, Company stockholders who do not vote in favor of the adoption of the merger agreement and who otherwise comply with the applicable provisions of Section 262 of the DGCL will be entitled to exercise appraisal rights thereunder. Any shares of Company common stock held by a Company stockholder as of the record date who has not voted in favor of the adoption of the merger agreement and who has validly made and not effectively withdrawn a demand for appraisal rights pursuant to Section 262 of the DGCL will not be converted into a right to receive the merger consideration unless such holder fails to perfect, withdraws or otherwise loses such holder's rights under Section 262 of the DGCL, or if a court of competent jurisdiction determines that such holder is not entitled to the relief provided by Section 262 of the DGCL. See "Appraisal Rights."

        Under the merger agreement, the Company must give Virtu (i) prompt notice of any demands for appraisal, withdrawals or attempted withdrawals of such demands, and any other instruments served pursuant to Section 262 of the DGCL and received by the Company relating to Section 262 of the DGCL and (ii) the opportunity to participate in and direct all negotiations and proceedings with respect to such notices and demands. The Company may not, except with the prior written consent of Virtu, make any payments with respect to any demands for appraisal or settle, compromise, offer to settle or compromise, or otherwise negotiate any such demands.

        THE PROCESS OF DEMANDING AND EXERCISING APPRAISAL RIGHTS REQUIRES STRICT COMPLIANCE WITH TECHNICAL PREREQUISITES. IF YOU WISH TO EXERCISE YOUR APPRAISAL RIGHTS, YOU SHOULD CONSULT WITH YOUR OWN LEGAL COUNSEL IN CONNECTION WITH COMPLIANCE UNDER SECTION 262 OF THE DGCL, THE FULL TEXT OF WHICH AS OF THE DATE HEREOF IS ATTACHED TO THIS PROXY STATEMENT AS ANNEX D.

Withholding

        Virtu and the paying agent will be entitled to deduct and withhold from the merger consideration the amounts they are required to deduct and withhold under the Code or any provision of state, local or foreign tax law. If any such amounts are withheld and paid over to the appropriate governmental

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entity, these amounts will be treated for all purposes of the merger agreement as having been paid to the stockholders from whom they were withheld.

Representations and Warranties

        The merger agreement contains representations and warranties of each of the Company and Virtu. The representations and warranties are subject, in some cases, to specified exceptions and qualifications contained in the merger agreement, information contained in certain public filings made by the Company with the SEC and information in the confidential disclosure schedules that the Company and Virtu each delivered in connection with the merger agreement. The representations and warranties in the merger agreement do not survive the effective time.

        Each of the Company and Virtu makes representations and warranties with respect to itself and its business regarding, among other things:

•

corporate matters, including due organization and qualification and subsidiaries;



•

corporate power and authority to own or lease its properties and assets and carry on its business;



•

authority relative to execution and delivery of the merger agreement and the absence of conflicts with, or violations of, organizational documents or other obligations as a result of the merger;



•

required governmental and other regulatory filings and consents and approvals in connection with the merger;



•

binding effect of the merger agreement;



•

legal proceedings;



•

broker's fees payable in connection with the merger; and



•

the accuracy of information supplied for inclusion in this proxy statement and other similar documents.

        In addition, certain representations and warranties are made only by the Company, including:

•

compliance with applicable laws;



•

capitalization;



•

compliance of documents filed with (or furnished to) the SEC by the Company with the published rules and regulations of the SEC;



•

certain material contracts and the absence of defaults related to such contracts;



•

absence of certain changes or events from December 31, 2016 through the date of the merger agreement;



•

tax matters;



•

labor relations matters;



•

employee and employee benefit plan matters;



•

absence of any material undisclosed liabilities;



•

intellectual property matters;



•

privacy of customer information;



•

environmental matters;

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•

insurance matters;



•

disclosure controls and procedures;



•

real property;



•

the accuracy of information supplied for inclusion in the information statement distributed by Virtu regarding the approval of the equity financing by its stockholders; and



•

related party transactions.

        In addition, certain representations and warranties are made only by Virtu and Merger Sub (which we refer to together as the "Acquirer Parties"), including:

•

ownership and operations of Merger Sub; and



•

financing matters and availability of funds.

        Certain representations and warranties of the Acquirer Parties and the Company are qualified as to knowledge, "materiality," "material adverse effect" or material delay or material impairment of the ability of the Acquirer Parties to consummate the merger and other transactions contemplated by the merger agreement on a timely basis.

        For purposes of the merger agreement, a "material adverse effect" with respect to the Company means any change, effect, event, occurrence, state of facts or development that (i) materially impairs or delays, or would reasonably be expected to materially impair or materially delay the Company's ability to consummate the merger or (ii) has a material adverse effect on the business, financial condition or results of operations of the Company and its subsidiaries, taken as a whole, excluding the impact of:

•

changes in global, national or regional economic or political (including results of elections) conditions (including any outbreak or escalation of hostilities or war or any act of terrorism) or changes in the securities, credit or financial markets;



•

changes, after the date of the merger agreement, adversely and generally affecting the industry in which the Company and its subsidiaries operates;



•

any failure, in and of itself, by the Company and its subsidiaries to meet any internal or external projections, forecasts or revenue or earnings predictions for any period ending after the date of the merger agreement;



•

changes, after the date of the merger agreement, in laws, or interpretations thereof by courts or governmental entities, applicable to the Company and its subsidiaries or any of their respective properties or assets or in U.S. generally accepted accounting principles or applicable accounting regulations;



•

public announcement of the transactions contemplated by the merger agreement;



•

any action or omission taken pursuant to the express terms of the merger agreement with the express prior written consent of the Acquirer Parties or any action taken by the Acquirer Parties after disclosure to the Acquirer Parties by the Company of all material and relevant facts and information to the knowledge of the Company;



•

any hurricane, tornado, flood, earthquake or other natural disaster; or



•

any pending, initiated or threatened stockholder litigation against the Company or any of its directors or officers relating to the merger agreement;

except that the first, second and fourth bullet points above will be taken into account to the extent that the effects of such change have a disproportionate impact on the Company and its subsidiaries, taken

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as a whole, as compared to other for-profit participants in the industry in which the Company and its subsidiaries conduct their businesses.

        For purposes of the merger agreement, a "material adverse effect" with respect to the Acquirer Parties means a material adverse effect on the ability of the Acquirer Parties to timely consummate the transactions contemplated by the merger agreement.

Covenants and Agreements

Conduct of Businesses Prior to the Completion of the Merger

        The Company has agreed to certain restrictions on itself and its subsidiaries, and its and their conduct of business, prior to the completion of the merger (or earlier termination of the merger agreement in accordance with its terms). In general, the Company will, and will cause each of its subsidiaries to, (i) conduct its and its subsidiaries' operations in the ordinary course of business consistent with past practice and (ii) use its reasonable best efforts to preserve intact the business organization of the Company and its subsidiaries and to preserve the goodwill of customers, suppliers and all other persons having business relationships with the Company and its subsidiaries.

        Without limiting the foregoing, prior to the completion of the merger (or earlier termination of the merger agreement in accordance with its terms), the Company has also agreed that, except as otherwise required by the merger agreement or as disclosed in the confidential disclosure schedule delivered by the Company to Virtu at the time of the merger agreement, the Company will not, and will not permit any of its subsidiaries to do any of the following without the prior written consent of Virtu (such consent not to be unreasonably withheld):

•

adopt or propose any change in its organizational documents;



•

engage in any material transaction (including capital expenditures) outside of the ordinary course of business that would require expenditures by the surviving corporation, Virtu or any of Virtu's subsidiaries in excess of $5 million per annum or $10 million in the aggregate;



•

issue, reissue, sell, grant, pledge or otherwise encumber, or authorize the issuance, reissuance, sale, grant, pledge or other encumbrance of shares of Company capital stock, or securities convertible into capital stock of any class of the Company, or any rights, warrants or options to acquire any convertible securities or capital stock of the Company (other than the issuance of shares of Company capital stock in connection with the exercise of Company equity awards or Company warrants, in each case outstanding as of the date of the merger agreement in accordance with the Company stock plan or the warrant agreement, respectively, in each case as in effect as of the date of the merger agreement);



•

(i) increase the compensation or benefits payable or provided to any current or former director, officer, employee or independent contractor, other than any such increases made in the ordinary course of business and consistent with past practice for employees whose total annual compensation does not exceed $300,000, (ii) grant or pay to any current or former director, officer, employee or independent contractor any severance, change in control or termination pay, or modifications thereto or increases therein, other than pursuant to any Company plan (as defined below) as in effect on the date hereof, in accordance with their terms as in effect on such date, (iii) pay any benefit or grant or amend any award (including in respect of stock options, stock appreciation rights, performance units, restricted stock or other stock-based or stock-related awards or the removal or modification of any restrictions in any Company plan or awards made thereunder) except as required to comply with any applicable law or any Company plan as in effect as of the date hereof, (iv) adopt, enter into, amend, modify or terminate any collective bargaining agreement or other labor union contract, (v) take any action to accelerate the vesting or payment of any compensation or benefit (including in respect of Company equity

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awards) under any Company plan or awards made thereunder or other contract with any current or former director, officer, employee or independent contractor of the Company or any of its subsidiaries, other than as required pursuant to the merger agreement, (vi) amend or terminate any, or enter into or adopt any new, Company plan or any other plan, trust, fund, policy, agreement or arrangement for the benefit of any current or former directors, officers, employees or independent contractors of the Company or any of its subsidiaries, other than in the ordinary course of business consistent with past practice and as would not have a material cost to the Company or its subsidiaries, (vii) hire any employee whose total annual compensation exceeds $300,000, or (viii) waive or materially amend any restrictive covenant entered into by any current or former director, officer, employee or independent contractor of the Company or any of its subsidiaries;

•

except in the ordinary course of business consistent with past practice, sell, lease, encumber or otherwise surrender, relinquish, dispose of, transfer, exclusively license, mortgage, pledge or grant any lien on any material assets, properties or rights (including the capital stock of its subsidiaries) except (i) to the extent they are used, retired or replaced in the ordinary course of business or (ii) to the Company or any subsidiary of the Company;



•

(i) declare, set aside or pay any dividends on, or make any other distributions (whether in cash, stock or property) in respect of, any of its capital stock, other than dividends or distributions declared, set aside, paid or made by a direct or indirect subsidiary of the Company to the Company or a subsidiary of the Company, (ii) adjust, split, combine or reclassify any of its capital stock or issue or propose or authorize the issuance of any other securities (including options, warrants, or any similar security exercisable for or convertible into, such other security) in respect of, in lieu of or in substitution for shares of its capital stock or (iii) purchase, redeem or otherwise acquire any shares of its capital stock or the capital stock of any of its subsidiaries or any other securities thereof or any rights, warrants or options to acquire any such shares or other securities, except for purchases, redemptions or other acquisitions of capital stock or other securities pursuant to an existing restricted stock purchase agreement with current or former employees and acceptance of shares of Company capital stock as payment for the exercise price of any outstanding Company stock options or for withholding taxes incurred in connection with the exercise of Company stock options or the vesting or settlement of other Company equity awards, in each case outstanding as of the date of the merger agreement;



•

make, change or revoke any material tax election, file any material amended tax return, settle or compromise any material claim, action, proceeding or assessment for taxes, change any method of tax accounting, enter into any closing agreement with respect to taxes or make or surrender any material claim for a refund of taxes, in each case except (i) as required by applicable tax law, or (ii) consistent with past practice;



•

take any action or omit to take any action or enter into any transaction which, to the knowledge of the Company, prior to taking or omitting to take any such action or prior to entering into any such transaction, has, or would reasonably be expected to have, the effect of materially delaying or otherwise materially impeding or preventing the consummation of the transactions contemplated by the merger agreement;



•

except in the ordinary course of business consistent with past practice, (i) modify, amend or terminate any material contract of the Company, (ii) enter into any successor agreement to an expiring material contract that changes the terms of the expiring material contract or (iii) enter into any new agreement that would have been considered a material contract if it were entered into at or prior to the date hereof, in each of cases (i), (ii) and (iii) if the effect of such action would be materially adverse to the Company and its subsidiaries, taken as a whole;

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•

incur any indebtedness in excess of $5 million in the aggregate or issue any debt securities or assume, guarantee or endorse, or otherwise as an accommodation become responsible for or cancel, the indebtedness of any person (other than the Company or any of the Company's subsidiaries), or make or authorize any material loan to any person (in each case other than loans or advances made to the Company or by the Company or any of its subsidiaries), other than indebtedness in replacement of existing indebtedness (provided that such replacement indebtedness shall be prepayable without premium or penalty and shall have a principal amount no greater than the principal amount of the indebtedness it replaces);



•

acquire or agree to acquire by merging or consolidating with, or by purchasing all or substantially all the assets of or all or substantially all the outstanding equity interests in, any business or any corporation, partnership, joint venture, limited liability company or other company, association or other business organization;



•

change any significant method of accounting or accounting principles or practices by the Company or any of its subsidiaries, except for such changes required by U.S. GAAP or applicable regulatory accounting requirements;



•

terminate, cancel, or materially amend or modify any material insurance policies maintained by the Company covering the Company or any of its subsidiaries or their respective properties which is not replaced by a comparable amount of insurance coverage;



•

adopt a plan of complete or partial liquidation, dissolution, restructuring, recapitalization or other reorganization of the Company or any of its subsidiaries;



•

abandon, encumber, convey title (in whole or in part), exclusively license or grant any right or other licenses to material intellectual property owned or exclusively licensed to the Company or any of its subsidiaries, or enter into licenses or agreements that impose material new restrictions upon the Company or any of its subsidiaries with respect to intellectual property owned by any third party, in each case, other than in the ordinary course of business consistent with past practice;



•

materially change any of the architecture or infrastructure of the Company's or any of its subsidiaries' network or information technology infrastructure systems or any material component thereof or any other material information technology assets of the Company, other than maintenance or upgrades to any product provided by any existing vendor of the Company or such subsidiary or otherwise in the ordinary course of business consistent with past practice;



•

institute, compromise, settle or agree to settle any claims (a) involving amounts in excess of $5 million individually or $15 million in the aggregate or (b) that would impose any material non-monetary obligation on the Company that would continue after the effective time; or



•

authorize or enter into any agreement or otherwise make any commitment to do any of the foregoing.

        For purposes of the merger agreement, "Company plan" means any plan (i) under which any employee or former employee of the Company or any of its subsidiaries or individual or sole proprietorship serving as a consultant or independent contractor to the Company or any of its subsidiaries has any present or future right to benefits and that the Company or any of its subsidiaries sponsors, maintains or contributes or is obligated to contribute, or (ii) with respect to which the Company or any of its subsidiaries has any actual or contingent liability.

        Additionally, prior to the completion of the merger (or earlier termination of the merger agreement), Virtu has agreed that, except as otherwise required by the merger agreement, Virtu will not, and will not permit any of its subsidiaries to, take any action or omit to take any action or enter into any transaction which, to the knowledge of Virtu, has, or would reasonably be expected to have, the effect of materially delaying or otherwise materially impeding or preventing the consummation of the transactions contemplated by the merger agreement.

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Regulatory Matters

        Virtu and the Company have agreed to cooperate and use their respective reasonable best efforts to promptly prepare and file all necessary documentation, to effect all applications, notices, petitions and filings, to obtain as promptly as practicable all consents, approvals, rulings and authorizations required by law, including of all third parties and governmental entities which are necessary or advisable to consummate the transactions contemplated by the merger agreement and to comply with the terms and conditions of all such permits, consents, approvals, rulings and authorizations of all such third parties and government entities. Without limitation to the foregoing, as soon as practicable and in no event later than 15 days after the date of the merger agreement, the parties agree to prepare and file any applications, notices and filings required to be filed with any regulatory agency in order to obtain the required governmental approvals. All such applications, notices and filings related to required governmental approvals were made on or before the date hereof.

        However, Virtu will not be required to take, and shall not be required to cause its affiliates to take, any action that would result in a material adverse effect on the surviving corporation and the Acquirer Parties on a combined basis after the merger.

        Virtu and the Company have also agreed to furnish each other with all information reasonably necessary or advisable in connection with any statement, filing, notice or application to any governmental entity in connection with the merger, as well as to promptly keep each other apprised of the status of matters related to the completion of the transactions contemplated by the merger agreement.

Employee Benefit Matters

        During the one-year period commencing at the effective time and ending on the first anniversary of the closing, Virtu has agreed to cause the surviving corporation to provide each Company employee who continues to be employed by the surviving corporation after the effective time (which we refer to as a "continuing employee") with (i) (x) base salary or base wage and (y) target annual cash bonus opportunities that are generally made available to similarly situated employees of Virtu or (ii) (x) base salary or base wage and (y) target annual cash bonus opportunities that are substantially comparable to those provided by the Company immediately prior to the effective time and (iii) employee benefits in the aggregate that are either (x) generally made available to similarly situated employees of Virtu or (y) substantially comparable to those provided by the Company immediately prior to the effective time. Virtu will or will cause the surviving corporation to provide to each continuing employee whose employment terminates during the one-year period with severance benefits pursuant to and in accordance with the Company's broad-based severance plan currently in effect, without taking into account any reduction in compensation paid to such continuing employee after the effective time.

        Following the effective time, with respect to any employee benefit plans of Virtu in which any continuing employees become eligible to participate (which we refer to as "new plans"), subject to certain customary exclusions, Virtu will or will cause the surviving corporation to: (i) waive all pre-existing conditions, exclusions, evidence of insurability and waiting periods except to the extent they would apply under the most closely analogous Company benefit plans; (ii) provide credit for any eligible expenses incurred prior to the effective time of the merger under a Company benefit plan in satisfying any applicable deductible, co-payment or out-of-pocket requirements under any new plans; and (iii) recognize all service of continuing employees for all purposes in any new plan to the same extent that such service was taken into account under the most closely analogous Company benefit plan prior to the effective time of the merger, provided that the service recognition shall not apply to the extent it would result in duplication of benefits for the same period of services, for purposes of benefit accrual under any defined benefit pension for purposes of qualifying for subsidized early retirement benefits.

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        Prior to the effective time, the Company will take irrevocable action, effective of and contingent upon the closing, to terminate the Company's voluntary deferred compensation, incentive unit and deferred cash plans. Virtu will or will cause the surviving corporation to distribute all balances in such plans to the applicable participants as soon as practicable following the closing through the surviving corporation's payroll.

Director and Officer Indemnification and Insurance

        The merger agreement provides that all rights, existing as of the date of the merger agreement, to indemnification, advancement of expenses and exculpation from liabilities for acts or omissions occurring at or prior to the completion of the merger in favor of the current or former officers, directors or employees of the Company or any of its subsidiaries will continue in full force and effect. The merger agreement also provides that, following completion of the merger, the surviving corporation will indemnify and hold harmless, to the fullest extent permitted by applicable law, all individuals who are, as of the date of the merger agreement and at any time from and after the date of the merger agreement until the completion of the merger, directors or officers of the Company and its subsidiaries (in their capacity as such), against any costs, claims, expenses and liabilities, whether arising before or after the effective time, arising out of the fact that such person is or was a director or officer of the Company or its subsidiaries, and pertaining to matters existing or occurring at or prior to the effective time, and will also advance expenses to such persons, provided that such person provides an undertaking to repay such advances if it is ultimately determined that such person is not entitled to indemnification.

        The merger agreement requires the surviving corporation to maintain, for a period of six years after completion of the merger, the Company's existing directors' and officers' liability insurance policy, or policies with a substantially comparable insurer of at least the same coverage and amounts and containing terms and conditions that are no less advantageous to the insured, with respect to claims against present and former officers and directors of the Company and its subsidiaries arising from facts or events that occurred at or prior to the completion of the merger. However, the surviving corporation is not required to spend annually more than 300% of the annual premium by the Company for such insurance for the year ended December 31, 2016 (which we refer to as the "maximum amount"), and if such premiums for such insurance would at any time exceed that amount, then Virtu will maintain policies of insurance which, in its good faith determination, provide the maximum coverage available at an annual premium equal to the maximum amount. If the surviving corporation is unable to obtain the insurance required by the merger agreement, it will obtain as much comparable insurance as possible for the years within such six-year period for an annual premium equal to the maximum amount, in respect of each policy year within such period. In lieu of such insurance, Virtu may direct the Company to obtain at or prior to the effective time a "tail" policy under the Company's existing directors' and officers' insurance policy. If the Company purchases such a "tail" policy, Virtu must maintain the policy in full force and effect and continue to honor its obligations under the policy.

Financing

        Pursuant to the merger agreement, Virtu is required to use its reasonable best efforts to consummate the equity financing and the debt financing. Further, in the event that any portion of the equity financing or the debt financing becomes unavailable, Virtu is required to use its reasonable best efforts to obtain as promptly as practicable alternate equity financing or debt financing, as the case may be, on terms not materially less favorable to Virtu. To the extent Virtu is unable to obtain any amount of alternate equity financing, Virtu is required to draw upon any additional amounts available under the debt financing to cover the shortfall.

        The Company has agreed to use its reasonable best efforts to provide to Virtu such reasonable cooperation that is customary in connection with the arrangement of the debt financing, as reasonably

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requested by Virtu, including by using its reasonable best efforts to (i) cause members of the Company's senior management and other representatives to be available, upon reasonable advance notice, to participate in a reasonable number of meetings, presentations, drafting sessions and due diligence sessions, (ii) furnish to Virtu as promptly as reasonably practicable information about the Company that the Company has agreed to provide in connection with preparing customary documents in connection with any offering document or marketing materials related to the debt financing, (iii) assist with the preparation of pro forma financial statements, (iv) issue customary representation letters to the Company's independent registered public accounting firm and using reasonable best efforts to obtain, consistent with customary practice, necessary consents to the inclusion of the Company's financial information and reports in connection with any offering document related to the debt financing; (v) provide customary authorization letters to debt financing sources; (vi) provide documentation required by applicable "know your customer" and anti-money laundering laws and regulations; (vii) assist with the preparation and execution of certain contracts for indebtedness, including the definitive agreements in connection with the debt financing; (viii) permit the debt financing sources to evaluate the Company's assets and cash management policies; (ix) take necessary corporate actions to effect the debt financing; (x) obtain customary evidence of authority and deliver other customary ancillary documents in connection with the closing of the debt financing; (xi) allow access to existing lending relationships of the Company and (xii) effect the payoff of the Company's Credit Agreement, dated June 5, 2015, among KCG Americas LLC, the Company, Bank of America, N.A., BMO Harris Bank N.A., and the financial institutions from time to time party thereto, concurrently with the closing of the merger.

        Virtu has agreed to, promptly upon written request by the Company, reimburse the Company for all reasonable and documented out-of-pocket costs incurred by the Company or its subsidiaries in connection with such cooperation provided by the Company.

        The obligations of Virtu and Merger Sub to complete the merger are not contingent upon the receipt of the financing.

Certain Additional Covenants

        The merger agreement also contains additional covenants, including, among others, covenants relating to the filing of this proxy statement, obtaining required consents, access to information, exemption from takeover laws, public announcements with respect to the transactions contemplated by the merger agreement, the taking of steps to cause dispositions of Company equity securities pursuant to the transactions contemplated by the merger agreement by directors and officers of the Company to be exempt under Rule 16b-3 promulgated under the Exchange Act, the delisting of Company common stock, cooperation with respect to stockholder litigation, integration, and employee matters and the taking of steps to satisfy and discharge the notes of the Company issued pursuant to the Indenture, dated March 13, 2015, between the Company and The Bank of New York Mellon, as Trustee.

Stockholder Meeting and Recommendation of the Company Board of Directors

        The Company has agreed to hold a meeting of its stockholders for the purpose of voting upon adoption of the merger agreement and other related matters as soon as reasonably practicable. The Company board has agreed to communicate to its stockholders its recommendation (and include such recommendation in this proxy statement) that they adopt the merger agreement.

        As discussed more fully below, the Company has agreed not to solicit any alternative proposal or offer to merge or acquire 20% or more of the Company. However, if (i) the Company board is presented with an unsolicited bona fide written takeover proposal and, after consultation with its outside counsel and, with respect to financial matters, its financial advisors, determines in good faith that such unsolicited bona fide written takeover proposal constitutes or is reasonably likely to result in

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a superior company proposal (defined below), or (ii) other than in connection with an unsolicited bona fide written takeover proposal, an event, fact, circumstance, development or occurrence that affects the business, assets or operations of the Company or its subsidiaries that is unknown to the Company board as of the date of the merger agreement becomes known to the Company board, and, in each case, the Company board concludes in good faith, following consultation with its outside legal counsel, that failure to make a company adverse recommendation change is reasonably likely to violate its fiduciary duties to the Company stockholders, then it may make a Company adverse recommendation change, provided that:

•

the Company gives Virtu at least five business days' prior written notice of its intention to take such action and certain information about the event or circumstances giving rise to its determination to take such action (including (i) in the case of a takeover proposal, the latest material terms and conditions of, and the identity of the third party in any such takeover proposal or any amendment or modification thereof or (ii) in the case of an unknown and not reasonably foreseeable intervening event, the nature of the intervening event); and



•

the Company board takes into account any changes to the merger agreement committed to in writing by Virtu (which shall be negotiated in good faith by the Company) that (i) in the event of a superior company proposal, result in a transaction that is no less favorable to the Company stockholders than any superior company proposal in the absence of such changes or (ii) in the event of an unknown and not reasonably foreseeable intervening event, the Company board would no longer be required to make a Company adverse recommendation change (defined below) in order not to be reasonably likely to violate its fiduciary duties to the Company stockholders. In the event Virtu agrees to make such changes to the merger agreement in either case of clause (i) or (ii) above, as applicable, no Company adverse recommendation change will be made.

        Notwithstanding any Company adverse recommendation change (defined below), unless the merger agreement has been terminated in accordance with its terms, the Company is required to convene the special meeting and to submit the merger agreement to a vote of Company stockholders.

        Except as set forth above, the Company board shall not, and shall not resolve or agree to, (i) withdraw or modify in any manner adverse to Virtu, or propose publicly to withdraw or modify in any manner adverse to Virtu, the Company recommendation, (ii) approve, recommend or declare advisable, or propose publicly to approve, recommend or declare advisable, any takeover proposal, (iii) approve, recommend or declare advisable, or propose publicly to approve, recommend or declare advisable, or allow the Company or any of its subsidiaries to enter into, any letter of intent, agreement in principle, memorandum of understanding, merger agreement, asset or share purchase or share exchange agreement, option agreement or other similar agreement related to any takeover proposal, (iv) enter into any agreement, letter of intent or agreement in principle requiring the Company to abandon, terminate or fail to consummate the merger, (v) fail to recommend against acceptance of any takeover proposal involving a tender offer or exchange offer for Company common stock within 10 business days after the commencement of such offer or (vi) fail to include the Company recommendation in the proxy statement or to re-affirm the Company recommendation within ten (10) business days of a request by Virtu to do so (any of the above a "Company adverse recommendation change").

        The Company may not adjourn, postpone or recess the special meeting without the prior written consent of Virtu and, unless there has been a Company adverse recommendation change, the Company must adjourn or postpone such meeting if there are insufficient shares of Company common stock represented (either in person or by proxy) to constitute a quorum necessary to conduct the business of the special meeting, or if on the date of such meeting the Company has not received proxies representing a sufficient number of shares necessary for adoption of the merger agreement (in each

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case, so long as such meeting is not adjourned, postponed or recessed to a date that is later than January 31, 2018).

Agreement Not to Solicit Other Offers

        The Company has agreed that it will not, and will cause its affiliates and its and their officers, directors or employees, agents, affiliates and representatives not to, directly or indirectly:

•

solicit or initiate, or knowingly encourage, induce or facilitate (including by way of providing information) any takeover proposal or any inquiry or proposal that constitutes or may reasonably be expected to result in a takeover proposal;



•

participate in any discussions or negotiations with any person regarding, or furnish to any person any information with respect to, or cooperate in any way with any person (whether or not a person making a takeover proposal) with respect to any takeover proposal or any inquiry or proposal that may reasonably be expected to result in a takeover proposal;



•

approve or recommend, or propose to approve or recommend, any takeover proposal;



•

approve or recommend, or propose to approve or recommend, or execute or enter into, any letter of intent, agreement in principle, memorandum of understanding, merger agreement, asset or share purchase or share exchange agreement, option agreement or other similar agreement related to any takeover proposal;



•

enter into any agreement or agreement in principle requiring the Company to abandon, terminate or fail to consummate the transactions contemplated by, or breach its obligations under, the merger agreement; or



•

propose or agree to do any of the foregoing.

        For purposes of the merger agreement, a "takeover proposal" means, other than the transactions contemplated by the merger agreement, any offer or proposal with respect to any (i) merger, consolidation, share exchange, other business combination or similar transaction involving the Company or any of its subsidiaries representing 20% or more of the assets of the Company and its subsidiaries, taken as a whole, (ii) direct or indirect acquisition of more than 20% of the outstanding shares of Company common stock or voting power of the Company, (iii) sale, lease, contribution or other disposition, directly or indirectly (including by way of merger, consolidation, share exchange, other business combination, partnership, joint venture, sale of capital stock of or other equity interests in the Company or any of its subsidiaries or otherwise) of any business or assets of the Company or any of its subsidiaries representing 20% or more of the consolidated revenues, net income or assets of the Company and its subsidiaries, taken as a whole, (iv) issuance, sale or other disposition, directly or indirectly, to any person (or the stockholders of any person) or group of securities (or options, rights or warrants to purchase, or securities convertible into or exchangeable for, such securities) representing 20% or more of the voting power of the Company, (v) any tender offer or exchange offer as a result of which any person or group shall acquire, directly or indirectly, beneficial ownership, or the right to acquire beneficial ownership, of 20% or more of the voting power of the Company or (vi) any combination of the foregoing.

        However, in the event that, prior to the adoption of the merger agreement by the Company's stockholders, the Company receives an unsolicited bona fide written takeover proposal, after the date of the merger agreement (which did not result from a breach of the Company's agreement not to solicit other offers) and the Company board concludes in good faith (after consultation with its outside counsel, and with respect to financial matters, its financial advisor) that such takeover proposal constitutes or is reasonably likely to result in a superior company proposal and that failure to make a Company adverse recommendation change is reasonably likely to violate its fiduciary duties to the

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stockholders under applicable law, the Company may (x) furnish information with respect to the Company and any of its subsidiaries to the third party making such takeover proposal pursuant to a confidentiality agreement with such third party on terms no less favorable to it than the confidentiality agreement between Virtu and the Company and which contains a customary standstill provision, so long as any material non-public information provided under this clause has previously been provided to Virtu or is provided to Virtu substantially concurrently with the time it is provided to such third party, and (y) participate in discussions regarding the terms of such takeover proposal and the negotiation of such terms with the third party making such takeover proposal; provided, that the Company will within 24 hours provide Virtu with any information with respect to the Company and any of its subsidiaries provided to such third party which was not previously provided to Virtu (or its representatives). The Company has agreed that neither it nor any of its subsidiaries will terminate, waive, amend, modify or fail to use reasonable best efforts to enforce any existing standstill, confidentiality or similar obligations owed by any third party to the Company or any of its subsidiaries under any outstanding agreement relating to a potential acquisition of the Company or any material portion of its assets, in each case except to the extent necessary to permit the Company to take an action it is otherwise permitted to take under the merger agreement; provided, that the Company has waived any such standstill obligation to the extent necessary to permit a third party otherwise covered by such standstill to submit a confidential unsolicited bona fide written takeover proposal to the Company board. The Company will within 24 hours advise Virtu orally of the receipt of any takeover proposal and the substance thereof (including the material terms and conditions of and the identity of the person making such takeover proposal), and will keep Virtu informed in all material respects of the status and details of the takeover proposal on a current basis, including any amendments to or revisions of the terms of such inquiry or takeover proposal.

        As used in the merger agreement, "superior company proposal" means a bona fide unsolicited written takeover proposal (substituting "50%" for "20%," in the definition thereof) which the Company board has determined in good faith, after consultation with outside counsel and financial advisors, (i) to be superior to the holders of Company common stock from a financial point of view than (x) the merger (including the merger consideration), taking into account all the terms and conditions of such proposal and the person making the proposal (including all financial, regulatory, legal conditions to consummation and other aspects of such proposal), and (y) the merger agreement (including any changes proposed by Virtu to the terms of the merger agreement), and (ii) is reasonably capable of being consummated on the terms proposed and (iii) for which all requisite cash funds are or will be immediately available or will be committed by identified financing sources at the time of signing a definitive transaction agreement.

Certain Permitted Disclosure

        Nothing in the merger agreement will prevent the Company or the Company board from complying with Rule 14a-9, Rule 14d-9 or Rule 14e-2(a) under the Exchange Act or Item 1012(a) of Regulation M-A under the Exchange Act, or from issuing a "stop, look and listen" statement pending disclosure of its position thereunder or making any legally required disclosure to the Company's stockholders if, in the good faith judgment of the Company, after consultation with its outside legal counsel, the failure to do so would be reasonably likely to result in a violation of its fiduciary duties under applicable law or such disclosure is otherwise required under applicable law.

Conditions to Complete the Merger

        The Acquirer Parties' and the Company's respective obligations to complete the merger are subject to the satisfaction or waiver of the following conditions:

•

the adoption of the merger agreement by the Company's stockholders;

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•

all required governmental approvals shall have been obtained;



•

the absence of any order, injunction, ruling, decree or judgment by any court or agency of competent jurisdiction or other legal restraint or prohibition (including the enactment or promulgation of any law, regulation or rule by any governmental authority or stock exchange or other self-regulatory organization with jurisdiction over the Company, Virtu or their respective subsidiaries) prohibits or makes illegal the completion of the merger;



•

twenty (20) days must have elapsed since Virtu distributed an information statement regarding the approval of the equity financing by its stockholders;



•

the accuracy of the representations and warranties contained in the merger agreement as of the date on which the merger agreement was entered into and as of the date on which the merger is completed, subject to the materiality standards provided in the merger agreement (and the receipt by each party of an officer's certificate from the other party to such effect); and



•

the performance by the other party in all material respects of all obligations required to be performed by it under the merger agreement at or prior to the date on which the merger is completed (and the receipt by each party of an officer's certificate from the other party to such effect).

        In addition, the Acquirer Parties will not be obligated to complete the merger if there has been a material adverse effect with respect to the Company since the date of the merger agreement.

        None of the Company, Virtu or Merger Sub can provide assurance as to when or if all of the conditions to the merger can or will be satisfied or waived by the appropriate party. As of the date of this proxy statement, the Company has no reason to believe that any of these conditions will not be satisfied.

Termination of the Merger Agreement

        The merger agreement can be terminated at any time prior to completion of the merger (whether before or after the adoption of the merger agreement by the Company stockholders (unless otherwise specified below)) in the following circumstances:

•

by the mutual written consent of Virtu and the Company;



•

by either Virtu or the Company if:



•

the merger has not been completed on or before January 31, 2018, except that, if the failure of the merger to be consummated by that date is primarily due to the breach by the party seeking to terminate the merger agreement of any representation, warranty, covenant or agreement contained in the merger agreement, such party shall not be permitted to terminate the merger agreement;



•

any injunction permanently restrains, enjoins or prohibits or makes illegal the consummation of the merger, and such injunction becomes effective (and final and nonappealable) or any law becomes enacted, entered, promulgated or enforced by any governmental authority that prohibits or makes illegal consummation of the merger;



•

Company stockholders do not approve the merger proposal;



•

by the Company, (i) if there has been a material breach of any representation, warranty, covenant or agreement on the part of Virtu or Merger Sub contained in the merger agreement, which breach would give rise to the failure of a condition to the Company's obligation to complete the merger and which is not curable or cured within the earlier of thirty (30) days and January 31, 2018, and (ii) the Company is not then in breach of any representation, warranty,

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covenant or agreement contained in the merger agreement such that it would give rise to the failure of a condition to Merger Sub's obligation to complete the merger;

•

by Virtu, (i) if there has been a material breach of any representation, warranty, covenant or agreement on the part of the Company contained in the merger agreement, which breach would give rise to the failure of a condition to Virtu's obligation to complete the merger and which is not curable or cured within the earlier of thirty (30) days and January 31, 2018, and (ii) Virtu is not then in breach of any representation, warranty, covenant or agreement contained in the merger agreement such that it would give rise to the failure of a condition precedent to the Company's obligation to complete the merger;



•

by Virtu if, prior to obtaining the approval of Company stockholders of the merger proposal:



•

the Company board fails to recommend to the Company stockholders that they approve the merger proposal, or effects a Company adverse recommendation change; or



•

the Company or the Company board has materially breached its obligations with respect to obtaining stockholder approval or not soliciting other offers in a manner adverse to Virtu.

Effect of Termination

        If the merger agreement is terminated, it will become void and have no effect, except that designated provisions of the merger agreement will survive the termination, including those relating to payment of a termination fee, expense reimbursement and the confidential treatment of information.

Termination Fee

        The Company will pay Virtu a termination fee in the amount of $45 million if the merger agreement is terminated in the following circumstances:

•

prior to obtaining the approval of Company stockholders of the merger proposal, Virtu terminates the merger agreement because the Company board fails to recommend to the Company stockholders that they approve the merger proposal or effects a Company adverse recommendation change;



•

prior to obtaining the approval of Company stockholders of the merger proposal, Virtu terminates the merger agreement because the Company or the Company board has materially breached its obligations with respect to obtaining stockholder approval or not soliciting other offers in a manner adverse to Virtu; and



•

prior to the Company stockholder meeting, (i) a Company takeover proposal is publicly made or otherwise communicated in writing to the Company's senior management or the Company board and not expressly withdrawn, and (ii) the merger agreement is terminated because (x) the Company stockholders fail to adopt the merger agreement at the special meeting, (y) a material breach of a representation, warranty, covenant or agreement by the Company results in the failure of a condition to Virtu's obligation to complete the merger and Virtu elects not to complete the merger or (z) the merger is not completed by January 31, 2018 and, in the case of (y) and (z), the approval of Company stockholders of the merger proposal has not been obtained at the time of such termination, and (iii) within 12 months of the termination of the merger agreement, the Company consummates a transaction (or enters into a definitive agreement to do so) with respect to a takeover proposal, provided that, for purposes of the foregoing, all references in the definition of takeover proposal to "20%" will instead refer to "50%".

        The Company will pay Virtu an amount equal to that required to reimburse Virtu and its affiliates for all of their documented out-of-pocket expenses in an amount not to exceed $15 million (and which

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will be credited against any termination fee owed in the event that Virtu would be entitled to both the termination fee and expense reimbursement) if the merger agreement is terminated by Virtu or the Company because the Company stockholder approval is not obtained at the Company stockholder meeting duly convened.

        Any termination fee that becomes due must be paid by wire transfer of same-day funds (i) under the circumstances described in the first or second bullet above, on the business day immediately following the date of termination of the merger agreement and (ii) under the circumstances described in the third bullet above, on the date of the first to occur of the events described in clause (iii) of that bullet.

        In the event that the termination fee becomes payable and is paid by the Company pursuant to the merger agreement, the termination fee will be Virtu's and Merger Sub's sole and exclusive remedy for monetary damages under the merger agreement.

Other Provisions

Expenses and Fees

        Unless a specific term of the merger agreement provides for a different arrangement, all costs and expenses incurred in connection with the merger agreement will be paid by the party incurring such expense, whether or not the merger is consummated, except that expenses incurred in connection with printing and mailing of this proxy statement and in connection with notices or other filings with any governmental authorities under any laws shall be shared equally by Virtu and the Company.

Amendment, Waiver and Extension of the Merger Agreement

        Subject to compliance with applicable law, the merger agreement may only be amended by an instrument or instruments in writing signed by, in the case of any modification or amendment, each of Virtu, Merger Sub and the Company, provided that any modification or amendment that is adverse in any respect to the financing sources must be consented to in writing by the financing sources, and provided further that after adoption of the merger agreement by the Company stockholders, there may not be, without further approval of such stockholders, any amendment of the merger agreement that requires further approval under applicable law.

Specific Performance

        The parties have agreed in the merger agreement that irreparable damage would occur in the event that any of the provisions of the merger agreement are not performed in accordance with their specific terms or are otherwise breached, and that monetary damages, even if available, would not be an adequate remedy. Accordingly, prior to the valid termination of the merger agreement, each of the parties is entitled to specific performance of the terms of the merger agreement, including an injunction or injunctions to prevent breaches of the merger agreement and to enforce specifically the terms and provisions of the merger agreement (including the obligation to consummate the merger) in addition to any other remedy to which such party is entitled at law or in equity. Each of the parties also waives, in the merger agreement, (i) any defense in any action for specific performance that a remedy of monetary damages would be adequate and (ii) any right to assert that a remedy of specific enforcement is unenforceable, invalid, contrary to law or inequitable for any reason.

        Notwithstanding anything to the contrary contained in the merger agreement, to the extent permitted by law, (i) the Company and its affiliates (other than Virtu and Merger Sub) will not commence or prosecute any claim, at law or in equity, against any financing source in connection with the merger agreement, the financing or the merger or the transactions contemplated by the financing,

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and (ii) no financing source shall be subject to any special, consequential, punitive or indirect damages or damages of a tortious nature.

Governing Law

        The merger agreement is governed by the laws of the State of Delaware, without giving effect to conflicts of laws principles that would cause the application of the law of any other jurisdiction, except that any claim, controversy or dispute of any kind or nature to which a financing source is a party that is in any way related to the merger agreement or any of the transactions contemplated thereby shall be governed by the laws of the State of New York.

No Third-Party Beneficiaries

        The merger agreement is not intended to and does not confer upon any person, other than the parties to the merger agreement and, as to certain provisions, the financing sources, any rights, remedies, obligations or liabilities under or by reason of the merger agreement, other than as described under "—Director and Officer Indemnification and Insurance" and "—Treatment of Company Equity Awards."

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VOTING AGREEMENT

        This section describes the material terms of the voting agreement. The description in this section and elsewhere in this proxy statement is qualified in its entirety by reference to the complete text of the voting agreement, which is attached as Annex B and is incorporated by reference into this proxy statement. This summary does not purport to be complete and may not contain all of the information about the voting agreement that is important to you. This section is not intended to provide you with any factual information about the Company or Virtu. Such information can be found elsewhere in this proxy statement and in the public filings the Company makes with the SEC, as described in "Where You Can Find More Information."

        As a condition and inducement to the willingness of Virtu and Merger Sub to enter into the merger agreement, concurrently with the execution and delivery of the merger agreement, Virtu and Merger Sub entered into a voting agreement with Jefferies, which beneficially owned approximately 23.4% of the outstanding Company common stock as of the record date. The voting agreement requires Jefferies to be present (in person or by proxy) and vote all of the Company common stock that Jefferies is entitled to vote at the special meeting or any other meeting of the Company's stockholders, and at any adjournment thereof, in favor of the adoption of the merger agreement and the approval of the transactions contemplated by the merger agreement, including the merger. Jefferies also agreed to vote all of its Company common stock against any action or agreement that would result in a material breach of any covenant, representation or warranty or any other obligation or agreement of the Company contained in the merger agreement, or of Jefferies contained in the voting agreement. Jefferies has also agreed to vote all of its Company common stock against any takeover proposal or any proposal relating to any takeover proposal and any other corporate action that would reasonably be expected to impede, interfere with, delay, postpone, adversely affect or prevent the consummation of the transactions contemplated by the merger agreement or the voting agreement, the performance by the Company of its obligations under the merger agreement or the performance by Jefferies of its obligations under the voting agreement, including any (i) extraordinary corporate transaction, such as a merger, consolidation, share exchange or other business combination involving the Company (other than the merger), (ii) a sale, lease or transfer of any material amount of assets of the Company or reorganization, recapitalization or liquidation of the Company or (iii) any change in the present capitalization of the Company or any amendment or other change to the Company's certificate of incorporation or bylaws.

        Jefferies also waived, and agreed not to exercise or assert, any appraisal or similar rights (including under Section 262 of the DGCL) in connection with the merger.

        Jefferies agreed that it will not (i) create or permit any encumbrance (other than certain permitted encumbrances) on its Company common stock, (ii) transfer, sell (including short sell), assign, gift, hedge, pledge, grant a participation interest in, hypothecate or otherwise dispose of, or enter into any derivative arrangement with respect to (collectively, "Transfer"), its Company common stock, (iii) enter into any contract with respect to any Transfer, (iv) grant or permit the grant of any proxy, power-of-attorney or other authorization or consent in or with respect to its Company common stock, (v) deposit or permit the deposit of any of its shares into a voting trust or enter into a voting agreement or arrangement with respect to its Company common stock or (vi) take or permit any other action that would restrict, limit or interfere with the performance of Jefferies' obligations under the voting agreement in any material respect.

        The voting agreement will terminate upon the earlier to occur of (i) the consummation of the merger and (ii) the termination of the merger agreement in accordance with its terms. The voting agreement will remain in force and effect following a Company adverse recommendation change. Jefferies will also have the right to terminate its voting agreement if the terms of the merger agreement are amended to reduce the consideration payable to Jefferies or otherwise materially and adversely

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impact Jefferies, and Virtu will also have the right to terminate the voting agreement by written notice to Jefferies.

        The foregoing description of the voting agreement is only a summary, and stockholders are urged to read the voting agreement attached as Annex B to this document, which is incorporated herein by reference.

        See "Security Ownership of Certain Beneficial Owners and Management."

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APPRAISAL RIGHTS

        If the merger agreement is adopted by Company stockholders, Company stockholders who do not vote in favor of the merger proposal and who properly demand appraisal of their shares will be entitled to appraisal rights in connection with the merger under Section 262 of the DGCL.

        The following discussion is not a complete statement of the law pertaining to appraisal rights under the DGCL and is qualified in its entirety by the full text of Section 262 of the DGCL, which is attached to this proxy statement as Annex D. The following summary does not constitute any legal or other advice nor does it constitute a recommendation that Company stockholders exercise their appraisal rights under Section 262 of the DGCL. Only a holder of record of shares of Company common stock is entitled to demand appraisal rights for the shares registered in that holder's name. A person having a beneficial interest in shares of Company common stock held of record in the name of another person, such as a bank, broker or other holder of record, must act promptly to cause the record holder to follow the steps summarized below properly and in a timely manner to perfect appraisal rights. If you hold your shares of Company common stock through a bank, broker or other holder of record and you wish to exercise appraisal rights, you should consult with the record holder of your shares.

        Under Section 262 of the DGCL, Company stockholders who (i) do not vote in favor of the merger proposal, (ii) are the record holders of such shares on the date on which they make a demand for appraisal and continue to hold such shares through the effective time and (iii) otherwise follow exactly the procedures set forth in Section 262 of the DGCL will be entitled to have their shares appraised by the Delaware Court of Chancery and to receive payment in cash of the "fair value" of such shares, exclusive of any element of value arising from the accomplishment or expectation of the merger, together with interest to be paid upon the amount determined to be fair value, if any (subject to proportionate reduction for any consideration paid to such stockholders prior to such determination), as determined by the Delaware Court of Chancery. For further information, see "Appraisal Rights—Determination of Fair Value."

        Under Section 262 of the DGCL, where a merger agreement is to be submitted for adoption at a meeting of stockholders, the corporation, not less than 20 days prior to the meeting, must notify each of its stockholders entitled to appraisal rights that appraisal rights are available and include in the notice a copy of Section 262 of the DGCL. This proxy statement constitutes the Company's notice to its stockholders that appraisal rights are available in connection with the merger, and the full text of Section 262 of the DGCL is attached to this proxy statement as Annex D. In connection with the merger, any Company stockholder who wishes to exercise appraisal rights, or who wishes to preserve such holder's right to do so, should review Annex D carefully.

        Failure to strictly comply with the requirements of Section 262 of the DGCL in a timely and proper manner will result in the loss of appraisal rights under the DGCL. A stockholder who loses its, his or her appraisal rights will be entitled to receive the merger consideration described in the merger agreement. Moreover, because of the complexity of the procedures for exercising the right to seek appraisal of shares of Company common stock, the Company believes that, if a stockholder considers exercising such rights, such stockholder should seek the advice of legal counsel.

        Stockholders wishing to exercise the right to seek an appraisal of their shares of Company common stock must do ALL of the following:

•

the stockholder must not vote in favor of the merger proposal. Because a proxy that is signed and submitted but does not otherwise contain voting instructions will, unless revoked, be voted in favor of the adoption of the merger agreement, a Company stockholder who votes by proxy and who wishes to exercise appraisal rights must vote against the proposal to adopt the merger agreement, abstain or not vote its shares;

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•

the stockholder must deliver to the Company a written demand for appraisal before the vote on the merger proposal at the special meeting;



•

the stockholder must continuously hold the shares from the date of making the demand through the effective time. A stockholder will lose appraisal rights if the stockholder transfers the shares before the effective time; and



•

the stockholder or the surviving corporation must file a petition in the Delaware Court of Chancery requesting a determination of the fair value of the shares within 120 days after the effective time. If no party files such petition for appraisal within 120 days after the effective time, then the stockholder will lose its right to an appraisal of its shares of Company common stock. The surviving corporation is under no obligation to file any petition and has no intention of doing so.

Filing Written Demand

        Any Company stockholder wishing to exercise appraisal rights must deliver to the Company, before the vote on the adoption of the merger agreement at the special meeting at which the merger proposal will be submitted to the Company stockholders, a written demand for the appraisal of the stockholder's shares, and that stockholder must not submit a blank proxy or vote in favor of the merger proposal. A Company stockholder wishing to exercise appraisal rights must hold of record the shares on the date the written demand for appraisal is made and must continue to hold the shares of record through the effective time. A Company stockholder must not submit a blank proxy or vote in favor of the merger proposal. A proxy that is submitted and does not contain voting instructions will, unless revoked, be voted in favor of the merger proposal, and it will constitute a waiver of the Company stockholder's right of appraisal and will nullify any previously delivered written demand for appraisal. Therefore, a Company stockholder who submits a proxy and who wishes to exercise appraisal rights must submit a proxy containing instructions to vote against the merger proposal or abstain from voting on the merger proposal. Neither voting against the merger proposal nor abstaining from voting on the merger proposal will, in and of itself, constitute a written demand for appraisal satisfying the requirements of Section 262 of the DGCL. The written demand for appraisal must be in addition to and separate from any proxy or vote on the merger proposal. A proxy or vote against the merger proposal will not constitute a demand. A stockholder's failure to make the written demand prior to the taking of the vote on the merger proposal at the special meeting will constitute a waiver of appraisal rights.

        Only a holder of record of shares of Company common stock is entitled to demand appraisal rights for the shares registered in that holder's name. A demand for appraisal in respect of shares of Company common stock should be executed by or on behalf of the holder of record, and must reasonably inform the Company of the identity of the holder and state that the holder intends thereby to demand appraisal of the holder's shares in connection with the merger. If the shares are owned of record in a fiduciary capacity, such as by a trustee, guardian or custodian, such demand must be executed by or on behalf of the record owner, and if the shares are owned of record by more than one person, as in a joint tenancy and tenancy in common, the demand should be executed by or on behalf of all joint owners. An authorized agent, including an authorized agent for two or more joint owners, may execute a demand for appraisal on behalf of a holder of record; however, the agent must identify the record owner or owners and expressly disclose that, in executing the demand, the agent is acting as agent for the record owner or owners.

        Stockholders who hold their shares in bank or brokerage accounts or other nominee forms, and who wish to exercise appraisal rights, should consult with their banks, brokers and other holders of record, as applicable, to determine the appropriate procedures for such record holder to make a demand for appraisal of those shares. A person having a beneficial interest in shares held of record in the name of another person, such as a bank, broker or other holder of record, must act promptly to

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cause the record holder to follow properly and in a timely manner the steps necessary to perfect appraisal rights. Shares held through banks, brokerage firms and other financial institutions are frequently deposited with and held of record in the name of a nominee of a central security depository, such as Cede & Co., The Depository Trust Company's nominee. Any beneficial holder of shares desiring to exercise appraisal rights with respect to such shares that are held through a bank, brokerage firm or other financial institution is responsible for ensuring that the demand for appraisal is made by the record holder. The stockholder should instruct such bank, brokerage firm or other financial institution that the demand for appraisal must be made by the record holder of the shares, which might be the name of a central security depositary if the shares have been so deposited.

        A record owner, such as a bank or broker, who holds shares of Company common stock as a nominee for others may exercise its, his or her right of appraisal with respect to the shares of Company common stock held for one or more beneficial owners, while not exercising this right for other beneficial owners. In that case, the written demand should state the number of shares of Company common stock as to which appraisal is sought. Where no number of shares of Company common stock is expressly mentioned, the demand will be presumed to cover all shares of Company common stock held in the name of the record owner.

        All written demands for appraisal pursuant to Section 262 of the DGCL should be mailed or delivered to:

KCG Holdings, Inc.
300 Vesey Street
New York, NY 10282
Telephone: (646) 682-6000
Attn: Corporate Secretary

        Any Company stockholder who has not commenced an appraisal proceeding or joined an appraisal proceeding as a named party may withdraw its, his or her demand for appraisal and accept the merger consideration by delivering to the surviving corporation a written withdrawal of the demand for appraisal within 60 days after the effective time. However, any such attempt to withdraw the demand made more than 60 days after the effective time will require written approval of the surviving corporation. No appraisal proceeding in the Delaware Court of Chancery will be dismissed without the approval of the Delaware Court of Chancery, and such approval may be conditioned upon such terms as the Delaware Court of Chancery deems just; however, such dismissal will not affect the right of any stockholder who has not commenced an appraisal proceeding, or joined that proceeding as a named party, to withdraw such stockholder's demand for appraisal and to accept the terms offered upon the merger within 60 days after the effective time.

Notice by the Surviving Corporation

        If the merger is completed, within 10 days after the effective time, the surviving corporation will notify each Company stockholder who has made a written demand for appraisal pursuant to Section 262 of the DGCL, and who has not voted in favor of the proposal to adopt the merger agreement, that the merger has become effective and the effective date thereof.

Filing a Petition for Appraisal

        Within 120 days after the effective time, but not thereafter, the surviving corporation or any Company stockholder who has complied with Section 262 of the DGCL and is entitled to appraisal rights under Section 262 of the DGCL may commence an appraisal proceeding by filing a petition in the Delaware Court of Chancery, with a copy served on the surviving corporation in the case of a petition filed by a stockholder, demanding a determination of the fair value of the shares held by all stockholders entitled to appraisal. The surviving corporation is under no obligation, and has no present

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intention, to file a petition, and holders should not assume that the surviving corporation will file a petition or initiate any negotiations with respect to the fair value of shares of Company common stock. Accordingly, any Company stockholders who desire to have their shares appraised should initiate all necessary action to perfect their appraisal rights in respect of their shares of Company common stock within the time and in the manner prescribed by Section 262 of the DGCL. The failure of a Company stockholder to file such a petition within the period specified in Section 262 of the DGCL could nullify the stockholder's previous written demand for appraisal.

        Within 120 days after the effective time, any Company stockholder who has complied with the requirements for exercise of appraisal rights will be entitled, upon written request, to receive from the surviving corporation a statement setting forth the aggregate number of shares not voted in favor of the merger proposal and with respect to which the Company has received demands for appraisal, and the aggregate number of holders of such shares. The surviving corporation must mail this statement to the requesting stockholder within 10 days after receipt of the written request for such a statement or within 10 days after the expiration of the period for delivery of demands for appraisal, whichever is later. A beneficial owner of shares held either in a voting trust or by a nominee on behalf of such person may, in such person's own name, file a petition seeking appraisal or request from the surviving corporation the foregoing statements. As noted above, however, the demand for appraisal can only be made by a stockholder of record.

        If a petition for an appraisal is duly filed by a Company stockholder and a copy thereof is served upon the surviving corporation, the surviving corporation will then be obligated, within 20 days after such service, to file in the office of the Register in Chancery in which the petition was filed a duly verified list containing the names and addresses of all stockholders who have demanded payment for their shares and with whom agreements as to the value of their shares have not been reached. After notice to the stockholders as required by the Delaware Court of Chancery, the court is empowered to conduct a hearing on the petition to determine those stockholders who have complied with Section 262 of the DGCL and who have become entitled to appraisal rights thereunder. The Delaware Court of Chancery may require the stockholders who demanded appraisal of their shares to submit their stock certificates to the Delaware Register in Chancery for notation thereon of the pendency of the appraisal proceedings, and if any stockholder fails to comply with the direction, the Delaware Court of Chancery may dismiss such stockholder from the proceedings.

Determination of Fair Value

        After determining the Company stockholders entitled to appraisal, the Delaware Court of Chancery will appraise the "fair value" of the shares of Company common stock, exclusive of any element of value arising from the accomplishment or expectation of the merger, together with interest, if any, to be paid upon the amount determined to be the fair value. In determining fair value, the Delaware Court of Chancery will take into account all relevant factors. Unless the court in its discretion determines otherwise for good cause shown, interest from the effective time through the date of payment of the judgment will be compounded quarterly and will accrue at 5% over the Federal Reserve discount rate (including any surcharge) as established from time to time during the period between the effective time and the date of payment of the judgment. At any time before the entry of judgment in the proceedings, the surviving corporation may pay to each Company stockholder entitled to appraisal an amount in cash, in which case interest shall accrue after such payment only upon the sum of (1) the difference, if any, between the amount so paid and the fair value of the shares as determined by the Delaware Court of Chancery, and (2) interest theretofore accrued, unless paid at that time. In Weinberger v. UOP,  Inc., the Delaware Supreme Court discussed the factors that could be considered in determining fair value in an appraisal proceeding, stating that "proof of value by any techniques or methods which are generally considered acceptable in the financial community and otherwise admissible in court" should be considered, and that "[f]air price obviously requires

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consideration of all relevant factors involving the value of a company." The Delaware Supreme Court stated that, in making this determination of fair value, the court must consider market value, asset value, dividends, earnings prospects, the nature of the enterprise, and any other facts that could be ascertained as of the date of the merger that throw any light on future prospects of the merged corporation. Section 262 of the DGCL provides that fair value is to be "exclusive of any element of value arising from the accomplishment or expectation of the merger." In Cede & Co. v. Technicolor,  Inc., the Delaware Supreme Court stated that such exclusion is a "narrow exclusion [that] does not encompass known elements of value," but which rather applies only to the speculative elements of value arising from such accomplishment or expectation. In Weinberger, the Delaware Supreme Court also stated that "elements of future value, including the nature of the enterprise, which are known or susceptible of proof as of the date of the merger and not the product of speculation, may be considered."

        Stockholders considering seeking appraisal should be aware that the fair value of their shares as so determined by the Delaware Court of Chancery could be more than, the same as or less than the consideration they would receive pursuant to the merger if they did not seek appraisal of their shares and that an opinion of an investment banking firm as to the fairness, from a financial point of view, of the consideration payable in a merger is not an opinion as to, and does not in any manner address, fair value under Section 262 of the DGCL. Although the Company believes that the merger consideration is fair, no representation is made as to the outcome of the appraisal of fair value as determined by the Delaware Court of Chancery, and stockholders should recognize that such an appraisal could result in a determination of a value higher or lower than, or the same as, the merger consideration. Neither the Company nor Virtu anticipates offering more than the merger consideration to any Company stockholder exercising appraisal rights, and each of the Company and Virtu reserves the right to assert, in any appraisal proceeding, that for purposes of Section 262 of the DGCL, the "fair value" of a share of Company common stock is less than the merger consideration. If a petition for appraisal is not timely filed, then the right to an appraisal will cease.

        The costs of the appraisal proceedings may be determined by the Delaware Court of Chancery and taxed upon the parties as the Delaware Court of Chancery deems equitable under the circumstances. Upon application of a stockholder, the Delaware Court of Chancery may also order that all or a portion of the expenses incurred by a stockholder in connection with an appraisal proceeding, including reasonable attorneys' fees and the fees and expenses of experts, be charged pro-rata against the value of all the shares entitled to be appraised.

        If any stockholder who demands appraisal of shares of Company common stock under Section 262 of the DGCL fails to perfect, or loses or successfully withdraws, such holder's right to appraisal, the stockholder's shares of Company common stock will be deemed to have been converted at the effective time into the right to receive the merger consideration, less applicable withholding taxes. A stockholder will fail to perfect, or effectively lose or withdraw, the holder's right to appraisal if no petition for appraisal is filed within 120 days after the effective time or if the stockholder delivers to the surviving corporation a written withdrawal of the holder's demand for appraisal and an acceptance of the merger consideration in accordance with Section 262 of the DGCL.

        From and after the effective time, no stockholder who has demanded appraisal rights will be entitled to vote such shares of Company common stock for any purpose, or to receive payment of dividends or other distributions on the stock, except dividends or other distributions on the holder's shares of Company common stock, if any, payable to Company stockholders of record as of a time prior to the effective time; however, if no petition for an appraisal is filed, or if the stockholder delivers to the surviving corporation a written withdrawal of the demand for an appraisal and an acceptance of the merger, either within 60 days after the effective time or thereafter with the written approval of the surviving corporation, then the right of such stockholder to an appraisal will cease. Once a petition for appraisal is filed with the Delaware Court of Chancery, however, the appraisal proceeding may not be

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dismissed as to any stockholder who commenced the proceeding or joined that proceeding as a named party without the approval of the court.

        Failure to comply strictly with all of the procedures set forth in Section 262 of the DGCL will result in the loss of a stockholder's statutory appraisal rights. Consequently, any Company stockholder wishing to exercise appraisal rights is encouraged to consult legal counsel before attempting to exercise those rights. To the extent there are any inconsistencies between the foregoing summary and Section 262 of the DGCL, Section 262 of the DGCL will govern.

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ADVISORY VOTE ON MERGER-RELATED COMPENSATION FOR THE
COMPANY'S NAMED EXECUTIVE OFFICERS

        This section sets forth the information required by Item 402(t) of Regulation S-K regarding the compensation for each named executive officer of the Company that is based on or otherwise relates to the merger. This compensation is referred to as "golden parachute" compensation by the applicable SEC disclosure rules, and in this section we use such term to describe the merger-related compensation payable to our named executive officers. The "golden parachute" compensation payable to these individuals is subject to a non-binding, advisory vote of the Company's stockholders, as described below in this section. None of Virtu's named executive officers will receive any compensatory payments or benefits that constitute "golden parachute" compensation within the meaning of Item 402(t) of Regulation S-K.

•

The estimated value of the payments and benefits that the Company's named executive officers will receive in connection with the merger is quantified below in accordance with Item 402(t) of Regulation S-K. The estimated values are based on (i) an assumption that the completion of the merger occurs on May 10, 2017 (the latest practicable date determined in accordance with Item 402(t) of Regulation S-K); (ii) a per share merger consideration of $20.00; (iii) salary and target bonus levels as of the date of this proxy statement; (iv) the number of unvested Company equity awards held by the named executive officers as of May 24, 2017, and (v) a qualifying termination of each named executive officer's employment immediately after the completion of the merger (or, for Mr. Allison, a termination of his employment where the Company elects to pay his base salary over a six-month period instead of giving advance notice of such termination).

        Depending on when the merger occurs, certain Company equity awards that are now unvested and included in the table below may vest independent of the merger pursuant to their terms based on continued service with the Company. In addition, the amounts indicated below are estimates based on multiple assumptions that may or may not actually occur, including assumptions described in this proxy statement, and do not reflect certain compensation actions that may occur before completion of the merger. As a result, the actual amounts, if any, to be received by a named executive officer may materially differ from the amounts set forth below. All dollar amounts have been rounded to the nearest whole dollar.

Golden Parachute Compensation

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