MPWR EVP & CFO now directly holds 125,630 shares after award

Rhea-AI Filing Summary

Monolithic Power Systems (MPWR) filed a Form 4 showing its EVP and CFO received 87,690 shares of common stock on October 25, 2025. The shares were awarded at $0 upon certification and approval of performance goals tied to market-based RSUs granted on October 25, 2022; all shares fully vested on October 25, 2025.

Following the award, the reporting person beneficially owns 125,630 shares directly. In addition, 5,331 shares are held indirectly in an Irrevocable Trust FBO Theodore F. Blegen and 5,331 shares are held indirectly in an Irrevocable Trust FBO Sarah N. Blegen.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

BLEGEN THEODORE

(Last) (First) (Middle)

5808 LAKE WASHINGTON BLVD NE

(Street)

KIRKLAND WA 98033

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MONOLITHIC POWER SYSTEMS INC [ MPWR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP and CFO

3. Date of Earliest Transaction (Month/Day/Year)
10/25/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	10/25/2025		A		87,690(1)	A	$0	125,630	D
Common Stock								5,331	I	Irrevocable Trust FBO Theodore F. Blegen
Common Stock								5,331	I	Irrevocable Trust FBO Sarah N. Blegen

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025, the Company's Compensation Committee of the Board of Directors certified and approved the achievement of the performance criteria for the MSUs, which resulted in 87,690 shares being awarded to the reporting person. All of the shares fully vested on October 25, 2025, pursuant to the grant agreement.

Remarks:

	/s/ Saria Tseng, attorney-in-fact for Mr. Bernie Blegen	10/27/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did MPWR's EVP & CFO report on Form 4?

An acquisition of 87,690 shares of common stock at $0 from vested market-based RSUs after performance certification on October 25, 2025.

What triggered the 87,690-share award for MPWR's CFO?

The Compensation Committee certified and approved achievement of performance criteria for MSUs granted on October 25, 2022.

How many MPWR shares does the CFO own after the transaction?

The reporting person beneficially owns 125,630 shares directly following the reported transaction.

Are there any indirect holdings reported by the MPWR CFO?

Yes. 5,331 shares in an Irrevocable Trust FBO Theodore F. Blegen and 5,331 shares in an Irrevocable Trust FBO Sarah N. Blegen.

What type of equity award led to the share acquisition for MPWR's CFO?

Market-based restricted stock units (MSUs) with stock price and relative TSR targets over a three-year period.

What was the transaction code and price for the MPWR Form 4 entry?

Transaction code A (acquired) at a price of $0.