5,781,126 Shares Square 1 Financial, Inc. Common Stock $0.01 par value per share Underwriting AgreementSquare 1 Financial Inc • April 1st, 2014 • State commercial banks • New York
Square 1 Financial, Inc., a Delaware corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to the Underwriters named in Schedule I hereto (the “Underwriters”), for whom Sandler O’Neill & Partners, L.P. is acting as Representative (the “Representative”), and certain shareholders of the Company named in Schedule II hereto (the “Selling Shareholders”) severally propose to sell to the Underwriters an aggregate of 5,781,126 shares (the “Firm Shares”) of common stock, $0.01 par value per share, of the Company (the “Common Stock”) of which 3,125,000 shares are to be issued and sold by the Company and 2,656,126 shares are to be sold by the Selling Shareholders in the respective amounts set forth opposite their respective names in Schedule II hereto. The Company and the Selling Shareholders also propose to sell to the Underwriters all or any part of 867,167 additional shares of Common Stock (the “Optional Shares”) in the respective amounts s
