[Form 4] Monolithic Power Systems, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Monolithic Power Systems director Jeff Zhou reported a sale of 400 shares of the company's common stock on 08/13/2025 at a price of $850 per share. After the reported transaction, Mr. Zhou beneficially owned 5,804 shares. The Form 4 was signed by an attorney-in-fact on behalf of Mr. Zhou.

Insights

Financial Analyst

TL;DR Insider director sold a small block of shares; ownership remains in the mid-thousands, suggesting routine liquidity activity.

The Form 4 discloses a single non-derivative sale of 400 shares by director Jeff Zhou at $850 per share, leaving 5,804 shares beneficially owned. This is a straightforward, one-off sale with no accompanying derivative transactions or indications of a planned 10b5-1 trading plan noted on the form. The transaction size relative to total beneficial ownership disclosed here is modest, consistent with ordinary portfolio management rather than a material change in control or stake.

Corporate Governance Expert

TL;DR Routine disclosure of an insider sale; signature by attorney-in-fact indicates permitted representation in filing.

The filing shows compliance with Section 16 reporting: a sale coded "S" on 08/13/2025 for 400 shares at $850 and a completed signature by an attorney-in-fact. There are no amendments, no derivative activity, and no boxes checked indicating a 10b5-1 plan on the face of the provided content. From a governance and disclosure perspective, the filing appears complete for the reported transaction.

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^*

Zhou Jeff

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/13/2025

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	08/13/2025		S		400	D	$850	5,804	D

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:

Remarks:

	/s/ Saria Tseng, attorney-in-fact for Mr. Jeff Zhou	08/13/2025
	** 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 Jeff Zhou report on the Form 4 for MPWR?

He reported a sale of 400 shares of Monolithic Power Systems common stock on 08/13/2025 at $850 per share.

How many shares does Jeff Zhou beneficially own after the transaction?

Following the reported sale, Mr. Zhou beneficially owned 5,804 shares.

Was the Form 4 for MPWR signed by the reporting person?

The form was signed on behalf of Mr. Jeff Zhou by an attorney-in-fact, Saria Tseng, on 08/13/2025.

Did the Form 4 disclose any derivative transactions or a 10b5-1 plan?

No derivative transactions are reported in the provided content, and the form does not indicate a 10b5-1 plan in the visible sections.

What transaction code was used on the Form 4?

The sale is marked with transaction code "S", indicating a sale of shares.