March 25, 2014
VIA EDGAR
U.S. Securities and Exchange Commission
Division of Corporation Finance
100 F Street, NE
Washington, DC 20549
| Re: | Square 1 Financial, Inc. |
Registration Statement on Form S-1, as amended (File No. 333-193197)
Request for Acceleration of Effectiveness
Ladies and Gentlemen:
Pursuant to Rule 461 under the Securities Act of 1933, as amended (the “Securities Act”), we, the undersigned representative of the participating underwriters (the “Representative”), hereby join in the request of Square 1 Financial, Inc. that the effective date of the above-referenced Registration Statement on Form S-1 be accelerated so that the Registration Statement will be declared effective at 3:00 p.m. on March 26, 2014, or as soon thereafter as practicable.
| Very truly yours, | ||
| SANDLER O’NEILL & PARTNERS, L.P. | ||
| As Representative of the Participating Underwriters | ||
| By: | /s/ Jennifer Docherty | |
| Name: |
Jennifer Docherty | |
| Title: |
Managing Director | |
cc: Michael R. Clampitt, Securities and Exchange Commission