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

Role
CEO, Director
Signature
/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing
Stock symbol
MPWR
Transactions as of
Oct 30, 2025
Transactions value $
-$133,698,936
Form type
4
Date filed
10/31/2025, 04:52 PM
Previous filing
Oct 28, 2025
Next filing
Nov 13, 2025
SEC
View on sec.gov

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 2025-10-30 0001308676

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MPWR Common Stock Tax liability -$134M -122K -10.91% $1,096.63 996K Oct 30, 2025 Direct F1
holding MPWR Common Stock 133K Oct 30, 2025 by M Hsing 04 Trust
holding MPWR Common Stock 12.8K Oct 30, 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.