X0603 D LIVE 0001329799 Square 1 Financial Inc 406 Blackwell Street SUITE 240 Durham NC 27701 910-692-4855 DELAWARE None None Corporation true Richard M. Casey 406 Blackwell Street Suite 240 Durham NC 27701 Executive Officer Director President & CEO Susan G. Casey 406 Blackwell Street Suite 240 Durham NC 27701 Executive Officer Director Executive Vice President Norman P. Creighton 406 Blackwell Street Suite 240 Durham NC 27701 Director Daniel R. Mathis 406 Blackwell Street Suite 240 Durham NC 27701 Director Stanley J. Bradshaw 406 Blackwell Street Suite 240 Durham NC 27701 Director William F. Grant, III 406 Blackwell Street Suite 240 Durham NC 27701 Director Robert S. Muelenbeck 406 Blackwell Street Suite 240 Durham NC 27701 Director Robert Scott 406 Blackwell Street Suite 240 Durham NC 27701 Director Lee Settle 406 Blackwell Street Suite 240 Durham NC 27701 Director James W. Ellison 406 Blackwell Street Suite 240 Durham NC 27701 Executive Officer Executive Vice President Christopher Woolley 406 Blackwell Street Suite 240 Durham NC 27701 Executive Officer Executive Vice President Judith E. Erwin 406 Blackwell Street Suite 240 Durham NC 27701 Executive Officer Executive Vice President Commercial Banking Decline to Disclose 06 false 2010-02-24 false true true false 0 N/A None Sandler O'Neill & Partners, L.P> 23328 919 Third Ave 6th Floor New York NY 10022 All States 48000000 1931250 46068750 Represents the issuance of 375,000 warrants to purchase shares of the Issuer's Class A common stock at an exercise price of $5.15 per share. Such warrants were immediately exercisable upon issuance. false 1 900000 1500000 Sandler O'Neill & Partners, L.P. will be paid a base fee of $1.5 million plus an amount equal to 5.0% of the aggregate securities purchase price in excess of $30.0 million, excluding sales of securities to designated investors. 0 false Square 1 Financial Inc /s/ Richard M. Casey Richard M. Casey President & CEO 2010-03-11