Monolithic Power Systems (MPWR) CEO gifts 12,337 shares to 501(c)(3) foundation

Rhea-AI Filing Summary

Monolithic Power Systems CEO and director Michael R. Hsing transferred 12,337 shares of common stock as a gift to a 501(c)(3) foundation on 12/09/2025. The company states that after the transfer he has no management or investment control and no pecuniary interest in those shares, and no funds were exchanged, so no sale occurred.

Following the transaction, Hsing beneficially owned 906,332 shares directly, plus 133,040 shares held indirectly through the M Hsing 04 Trust and 12,825 shares held indirectly through the ZH Family 2020 Trust.

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
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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^*

Hsing Michael

(Last) (First) (Middle)

1555 PALM BEACH LAKES BLVD.

(Street)

WEST PALM BEACH FL 33401

(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
X	Officer (give title below)		Other (specify below)
	CEO

3. Date of Earliest Transaction (Month/Day/Year)
12/09/2025

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	12/09/2025		G		12,337(1)	D	$0	906,332	D
Common Stock								133,040	I	by M Hsing 04 Trust
Common Stock								12,825	I	ZH Family 2020 Trust

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. The reported transaction involved a transfer of securities by gift from the reporting person's direct holdings to a 501(c)(3) foundation. The Company has determined that the reporting person does not have any management or investment control or any other pecuniary interest in the shares after the transfer. No funds were exchanged and no sale of shares occurred in the transfer.

Remarks:

	/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing	12/09/2025
	** 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 insider stock transaction did Monolithic Power Systems (MPWR) report?

The CEO and director of Monolithic Power Systems, Michael R. Hsing, reported a gift transfer of 12,337 shares of common stock on 12/09/2025.

Who received the 12,337 MPWR shares gifted by the CEO?

The 12,337 common shares were transferred by gift from Michael R. Hsing’s direct holdings to a 501(c)(3) foundation.

Did the Monolithic Power Systems CEO receive any cash from this stock transfer?

No funds were exchanged in the transfer, and the company notes that no sale of shares occurred in connection with this gift.

Does the MPWR CEO retain any interest in the gifted shares?

The company determined that after the transfer, Michael R. Hsing has no management or investment control and no pecuniary interest in the gifted shares.

How many Monolithic Power Systems shares does Michael R. Hsing own after the gift?

After the transaction, he beneficially owned 906,332 shares directly, plus 133,040 shares indirectly via the M Hsing 04 Trust and 12,825 shares indirectly via the ZH Family 2020 Trust.