SCHEDULE 13G

CUSIP No.

014442107

Names of Reporting Persons

Arnon Rosenthal

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 4,283,550.00
6	Shared Voting Power 3,930,375.00
7	Sole Dispositive Power 4,283,550.00
8	Shared Dispositive Power 3,930,375.00

Aggregate Amount Beneficially Owned by Each Reporting Person

8,213,925.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

7.4 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: With respect to Rows 5, 7, and 9, includes: (i) 1,736,295 shares of common stock held of record by Arnon Rosenthal (the "Reporting Person"), (ii) 132,804 shares of common stock that are issuable upon vesting of restricted stock units within 60 days of December 31, 2025 to the Reporting Person, and (iii) 2,414,451 shares of common stock that are issuable upon exercise of outstanding options within 60 days of December 31, 2025 to the Reporting Person. With respect to Rows 6, 8, and 9, includes (i) 1,972,875 shares of common stock held of record by The Rosenthal Family Revocable Trust Dated November 4, 1994, as restated on June 9, 1999, for which the Reporting Person serves as trustee; (ii) 652,500 shares of common stock held of record by The Adi Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee; (iii) 652,500 shares of common stock held of record by The Noam Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee and (iv) 652,500 shares of common stock held of record by The Shani Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee. With respect to Row 11, the percentage ownership is based on 109,151,472 shares of the Issuer's common stock outstanding as of October 31, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the Securities and Exchange Commission on November 6, 2025.

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

Alector, Inc.

(b)

Address of issuer's principal executive offices:

131 Oyster Point Blvd., Suite 600 South San Francisco, California 94080

Item 2.

(a)

Name of person filing:

Arnon Rosenthal

(b)

Address or principal business office or, if none, residence:

c/o Alector, Inc. 131 Oyster Point Blvd., Suite 600 South San Francisco, California 94080

(c)

Citizenship:

United States

(d)

Title of class of securities:

Common Stock, $0.0001 par value per share

(e)

CUSIP No.:

014442107

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:

(k)

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a)

Amount beneficially owned:

See Row 9 of cover page.

(b)

Percent of class:

See Row 5 of cover page for the Reporting Person.

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

See Row 11 of cover page.

(ii) Shared power to vote or to direct the vote:

See Row 6 of cover page for the Reporting Person.

(iii) Sole power to dispose or to direct the disposition of:

See Row 7 of cover page for the Reporting Person.

(iv) Shared power to dispose or to direct the disposition of:

See Row 8 of cover page for the Reporting Person.

Item 5.

Ownership of 5 Percent or Less of a Class.

Not Applicable

Item 6.

Ownership of more than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable

Item 8.

Identification and Classification of Members of the Group.

Not Applicable

Item 9.

Notice of Dissolution of Group.

Not Applicable

Item 10.

Certifications:

Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Arnon Rosenthal

Signature:	/s/Arnon Rosenthal
Name/Title:	Arnon Rosenthal
Date:	02/04/2026