X0304 4 2012-02-17 0 0001280452 MONOLITHIC POWER SYSTEMS INC MPWR 0001192171 CHANG KUO WEI HERBERT 6409 GUADALUPE MINES ROAD SAN JOSE CA 95120 1 0 0 0 Common Stock 2012-02-17 4 S 0 400.0 18.54 D 30789.0 I By Investar Capital Common Stock 2012-02-17 4 S 0 612.0 18.5 D 30177.0 I By Investar Capital Common Stock 91035.0 D By: Saria Tseng For: Herbert Chang 2012-02-17