X0306 4 2015-04-20 0 0001595974 RUBICON PROJECT, INC. RUBI 0001111909 RAIFMAN GREGORY R C/O THE RUBICON PROJECT, INC. 12181 BLUFF CREEK DRIVE, 4TH FLOOR LOS ANGELES CA 90094 1 1 0 0 President Common Stock 2015-04-20 4 A 0 27005 0.00 A 285503 D Reflects vesting of shares of performance-based restricted stock issued on October 20, 2014. The shares vested as a result of achievement of superior performance of the Issuer's common stock compared to the NASDAQ Internet Total Return index, as determined by the Compensation Committee of the Issuer's Board of Directors on April 20, 2015. /s/ Jonathan Feldman, attorney-in-fact 2015-04-22