MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2025

Aug 21, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2025-08-19

Reporting Person: Sciammas Maurice (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-08-19	Common Stock	G	1000	—	Disposed	1000	Indirect
2025-08-19	Common Stock	G	1499	—	Disposed	12228	Indirect
2025-08-19	Common Stock	G	1499	—	Acquired	1499	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	102325	Direct
Common Stock	44930	Indirect
Common Stock	1699	Indirect
Common Stock	1699	Indirect
Common Stock	1699	Indirect
Common Stock	2000	Indirect
Common Stock	5000	Indirect
Common Stock	9481	Indirect
Common Stock	9481	Indirect
Common Stock	1499	Indirect
Common Stock	4015	Indirect

Footnotes

F1: 1,000 shares were distributed from the Peter Rafferty and Eric Toothill 2021 Irrevocable Trust, on which the reporting person is a Trustee, to an individual who is not an immediate family member living in the same household of the reporting person. In addition, the Company has determined that the reporting person does not have any management or investment control or any other pecuniary interests over the shares. No funds were exchanged and no sale of shares occurred in the transfer.

F2: 1,499 shares were distributed from the Sciammas Siblings 2021 GRATs, on which the reporting person is a Trustee, to the Rosalind Sciammas brokerage account. No funds were exchanged, and no sale of shares occurred in the transfer.

F3: 1,499 shares were received by the Rosalind Sciammas brokerage account from Sciammas Siblings 2021 GRATs. No funds were exchanged, and no sale of shares occurred in the transfer