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: 2026-05-13 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: 2026-05-13 | Code: G (Gift) Shares: -1,563 | Price: $0.00 Shares Owned After: 25,097 | Ownership: I (Indirect) | Nature: Various Sciammas GRATs Footnotes: [F1] 1,563 shares were transferred from three GRATs, of which the reporting person is a Trustee, to the Sciammas Family Trust, of which the reporting person is a Trustee. No funds were exchanged, and no sale of shares occurred in the transfer. [Transaction #2] Security: Common Stock Date: 2026-05-13 | Code: G (Gift) Shares: +1,563 | Price: $0.00 Shares Owned After: 51,023 | Ownership: I (Indirect) | Nature: Sciammas Family Trust Footnotes: [F2] 1,563 shares were received by the Sciammas Family Trust, of which the reporting person is a Trustee, and transferred from three GRATs, of which the reporting person is a Trustee. No funds were exchanged and no sale of shares occurred in the transfer. --- Holdings --- [Holding #1] Security: Common Stock Ownership: I (Indirect) [Holding #2] Security: Common Stock Ownership: I (Indirect) [Holding #3] Security: Common Stock Ownership: I (Indirect) [Holding #4] Security: Common Stock Ownership: D (Direct) [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) --- Footnotes (Complete Index) --- F1: 1,563 shares were transferred from three GRATs, of which the reporting person is a Trustee, to the Sciammas Family Trust, of which the reporting person is a Trustee. No funds were exchanged, and no sale of shares occurred in the transfer. F2: 1,563 shares were received by the Sciammas Family Trust, of which the reporting person is a Trustee, and transferred from three GRATs, of which the reporting person is a Trustee. No funds were exchanged and no sale of shares occurred in the transfer. --- Signature --- /s/ /s/ Saria Tseng, attorney-in-fact for Mr. Maurice Sciammas (2026-05-15)