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: DEAN ROBERT W II CIK: 0001445300 Role: Officer (Interim CFO) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-05-13 | Code: J (Other acquisition/disposition) Shares: -2,156 | Price: $0.00 Shares Owned After: 5,904 | Ownership: D (Direct) Footnotes: [F1] The reported transaction involved a transfer of securities from the reporting person's direct holdings to an individual who is not an immediate family member sharing the same household. No funds were exchanged and no sale of shares occurred in the transfer. Following the completion of the transfer, the reporting person no longer retains any pecuniary interest in the shares. --- Holdings --- [Holding #1] Security: Common Stock Ownership: I (Indirect) --- Footnotes (Complete Index) --- F1: The reported transaction involved a transfer of securities from the reporting person's direct holdings to an individual who is not an immediate family member sharing the same household. No funds were exchanged and no sale of shares occurred in the transfer. Following the completion of the transfer, the reporting person no longer retains any pecuniary interest in the shares. --- Signature --- /s/ /s/ Saria Tseng, attorney-in-fact for Mr. Robert W. Dean II (2026-05-15)