Saria Tseng, EVP & General Counsel of Monolithic Power Systems, Sells 8,163 Shares Under 10b5-1 Plan

This Form 4 filing reports that Saria Tseng, Executive Vice President and General Counsel of Monolithic Power Systems Inc. (MPWR), sold 8,163 shares of common stock on April 8, 2026, through multiple transactions executed under a Rule 10b5-1 trading plan adopted on November 28, 2025. The sales occurred at prices ranging from approximately $1,264 to $1,322 per share, with total proceeds exceeding $10.6 million. Following these transactions, Tseng's direct ownership decreased to 156,983 shares, while she maintains an indirect ownership of 1,000 shares through the C&T Discovery Foundation. The filing indicates that all transactions were pre-scheduled under the 10b5-1 plan, which provides an affirmative defense against insider trading allegations by establishing predetermined trading parameters. The sales represent a significant reduction in Tseng's direct holdings, though she remains a substantial shareholder in the semiconductor company.