Monolithic Power Systems (MPWR)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-02-03 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: MONOLITHIC POWER SYSTEMS INC (MPWR) CIK: 0001280452 --- Reporting Owner --- Name: Hsing Michael CIK: 0001308676 Role: Director, Officer (CEO) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-02-03 | Code: A (Grant or award) Shares: +136,825 | Price: $0.00 Shares Owned After: 1,043,157 | Ownership: D (Direct) Footnotes: [F1] On February 7, 2023, the reporting person was granted performance-based restricted stock units ("PSUs") subject to the achievement of performance conditions over a three-year performance period. On February 3, 2026, the Company's Compensation Committee of the Board of Directors certified and approved the achievement of the performance criteria for the PSUs, which resulted in 136,825 shares being awarded to the reporting person, subject to tax withholdings. All of the shares fully vested and were released on February 3, 2026, pursuant to the grant agreement. --- Holdings --- [Holding #1] Security: Common Stock Ownership: I (Indirect) [Holding #2] Security: Common Stock Ownership: I (Indirect) --- Footnotes (Complete Index) --- F1: On February 7, 2023, the reporting person was granted performance-based restricted stock units ("PSUs") subject to the achievement of performance conditions over a three-year performance period. On February 3, 2026, the Company's Compensation Committee of the Board of Directors certified and approved the achievement of the performance criteria for the PSUs, which resulted in 136,825 shares being awarded to the reporting person, subject to tax withholdings. All of the shares fully vested and were released on February 3, 2026, pursuant to the grant agreement. --- Signature --- /s/ /s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing (2026-02-03)