Monolithic Power (NASDAQ: MPWR) EVP & counsel receives 57,170 PSUs

Rhea-AI Filing Summary

Monolithic Power Systems EVP & General Counsel Saria Tseng received 57,170 common shares on February 3, 2026 from previously granted performance-based restricted stock units. The company’s Compensation Committee certified that three-year performance goals were achieved, causing all units to fully vest and be released the same day at a price of $0 per share.

After this award, Tseng directly beneficially owned 223,501 shares of Monolithic Power Systems common stock and indirectly held 1,000 additional shares through C&T Discovery Foundation.

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^*

Tseng Saria

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP & General Counsel

3. Date of Earliest Transaction (Month/Day/Year)
02/03/2026

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	02/03/2026		A		57,170(1)	A	$0	223,501	D
Common Stock								1,000	I	C&T Discovery Foundation

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 February 7, 2023, the reporting person was granted performance-based restricted stock units ("PSUs") subject to the achievement of performance conditions over a three-year performance period. On February 3, 2026, the Company's Compensation Committee of the Board of Directors certified and approved the achievement of the performance criteria for the PSUs, which resulted in 57,170 shares being awarded to the reporting person, subject to tax withholdings. All of the shares fully vested and were released on February 3, 2026, pursuant to the grant agreement.

Remarks:

	/s/ Saria Tseng	02/03/2026
	** 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 transaction did MPWR report for Saria Tseng on February 3, 2026?

Monolithic Power Systems reported that EVP & General Counsel Saria Tseng acquired 57,170 common shares on February 3, 2026. These shares came from previously granted performance-based restricted stock units that fully vested when the company certified achievement of its three-year performance goals.

How did Saria Tseng receive the 57,170 MPWR shares disclosed in this Form 4?

Tseng received 57,170 shares at $0 per share upon vesting of performance-based restricted stock units granted February 7, 2023. The Compensation Committee certified that required performance conditions over a three-year period were met, triggering full vesting and release of the shares on February 3, 2026.

What is Saria Tseng’s MPWR share ownership after the February 2026 award?

Following the February 3, 2026 transaction, Tseng directly beneficially owned 223,501 Monolithic Power Systems common shares. In addition, 1,000 shares were reported as indirectly owned through C&T Discovery Foundation, reflecting both personal and affiliated holdings in the issuer’s stock.

What role does Saria Tseng hold at Monolithic Power Systems (MPWR)?

In this filing, Saria Tseng is identified as an officer of Monolithic Power Systems, serving as Executive Vice President & General Counsel. The Form 4 confirms officer status and indicates the reported stock award relates to her executive compensation in that role.

Were the 57,170 MPWR shares part of a performance-based equity plan?

Yes. The 57,170 shares resulted from performance-based restricted stock units granted February 7, 2023. These PSUs were subject to achievement of performance conditions over a three-year period, and fully vested after the Compensation Committee certified that the performance criteria were achieved on February 3, 2026.