Michael Hsing - 10 Feb 2026 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
10 Feb 2026
Net transactions value
-$38,837,435
Form type
4
Filing time
12 Feb 2026, 14:45:22 UTC
Previous filing
10 Feb 2026
Next filing
13 Feb 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Hsing Michael CEO, Director 1555 PALM BEACH LAKES BLVD., WEST PALM BEACH /s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing 12 Feb 2026 0001308676

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MPWR Common Stock Sale $4,869,907 -4,302 -0.44% $1132.01 983,932 10 Feb 2026 Direct F1, F2
transaction MPWR Common Stock Sale $7,189,944 -6,325 -0.64% $1136.75 977,607 10 Feb 2026 Direct F1, F3
transaction MPWR Common Stock Sale $18,361,430 -16,080 -1.6% $1141.88 961,527 10 Feb 2026 Direct F1, F4
transaction MPWR Common Stock Sale $4,427,758 -3,864 -0.4% $1145.90 957,663 10 Feb 2026 Direct F1, F5
transaction MPWR Common Stock Sale $1,398,599 -1,215 -0.13% $1151.11 956,448 10 Feb 2026 Direct F1, F6
transaction MPWR Common Stock Sale $801,542 -694 -0.07% $1154.96 955,754 10 Feb 2026 Direct F1, F7
transaction MPWR Common Stock Sale $418,108 -360 -0.04% $1161.41 955,394 10 Feb 2026 Direct F1, F8
transaction MPWR Common Stock Sale $1,034,915 -880 -0.09% $1176.04 954,514 10 Feb 2026 Direct F1, F9
transaction MPWR Common Stock Sale $335,233 -280 -0.03% $1197.26 954,234 10 Feb 2026 Direct F1
holding MPWR Common Stock 133,040 10 Feb 2026 by M Hsing 04 Trust
holding MPWR Common Stock 12,825 10 Feb 2026 ZH Family 2020 Trust
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 08/28/2025.
F2 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,128.88 to $1,133.86. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F3 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,133.92 to $1,138.90. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F4 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,138.96 to $1,143.96. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F5 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,144.03 to $1,149.00. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F6 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,149.04 to $1,154.00. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F7 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,154.09 to $1,155.86. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F8 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,159.96 to $1,163.96. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
F9 The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,172.65 to $1,177.08. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.