Michael Hsing - 30 Oct 2025 Form 4 Insider Report for MONOLITHIC POWER SYSTEMS INC (MPWR)

Signature
/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing
Issuer symbol
MPWR
Transactions as of
30 Oct 2025
Net transactions value
-$133,698,936
Form type
4
Filing time
31 Oct 2025, 16:52:23 UTC
Previous filing
28 Oct 2025
Next filing
13 Nov 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Hsing Michael CEO, Director 5808 LAKE WASHINGTON BLVD NE, KIRKLAND /s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing 30 Oct 2025 0001308676

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MPWR Common Stock Tax liability $133,698,936 -121,918 -11% $1096.63 995,669 30 Oct 2025 Direct F1
holding MPWR Common Stock 133,040 30 Oct 2025 by M Hsing 04 Trust
holding MPWR Common Stock 12,825 30 Oct 2025 ZH Family 2020 Trust
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a Form 4.