MONOLITHIC POWER SYSTEMS INC (MPWR) · Insider Trading (Form 4) SEC Filing

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-05-29 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: MONOLITHIC POWER SYSTEMS INC (MPWR) CIK: 0001280452 --- Reporting Owner --- Name: Sciammas Maurice CIK: 0001360833 Role: Officer (EVP, WW Sales & Marketing) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-05-29 | Code: G (Gift) Shares: -12,472 | Price: $0.00 Shares Owned After: 12,625 | Ownership: I (Indirect) | Nature: Various Sciammas GRATs Footnotes: [F1] The reported transaction involved distributions of securities from the various GRATs, of which the reporting person is a trustee, to individuals who are not immediate family members sharing the same household. No funds were exchanged and no sale of shares occurred in the distributions. Following the completion of the distributions, neither the GRATs nor the reporting person retains any pecuniary interest in the shares. --- Holdings --- [Holding #1] Security: Common Stock Ownership: D (Direct) [Holding #2] Security: Common Stock Ownership: I (Indirect) [Holding #3] Security: Common Stock Ownership: I (Indirect) [Holding #4] Security: Common Stock Ownership: I (Indirect) [Holding #5] Security: Common Stock Ownership: I (Indirect) [Holding #6] Security: Common Stock Ownership: I (Indirect) [Holding #7] Security: Common Stock Ownership: I (Indirect) [Holding #8] Security: Common Stock Ownership: I (Indirect) [Holding #9] Security: Common Stock Ownership: I (Indirect) [Holding #10] Security: Common Stock Ownership: I (Indirect) [Holding #11] Security: Common Stock Ownership: I (Indirect) --- Footnotes (Complete Index) --- F1: The reported transaction involved distributions of securities from the various GRATs, of which the reporting person is a trustee, to individuals who are not immediate family members sharing the same household. No funds were exchanged and no sale of shares occurred in the distributions. Following the completion of the distributions, neither the GRATs nor the reporting person retains any pecuniary interest in the shares. --- Signature --- /s/ /s/ Saria Tseng, attorney-in-fact for Mr. Maurice Sciammas (2026-06-02)