Monolithic Power Systems (MPWR) EVP awarded 57,170-share PSU payout

Rhea-AI Filing Summary

Monolithic Power Systems executive Maurice Sciammas reported a stock award tied to prior performance-based units. As EVP, WW Sales & Marketing, he received 57,170 shares of common stock on February 3, 2026, at a price of $0 after the company’s Compensation Committee certified performance goals for PSUs granted on February 7, 2023.

All 57,170 shares fully vested and were released the same day, bringing his directly held common stock to 201,500 shares. Additional indirect holdings are reported in various family trusts and accounts.

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^*

Sciammas Maurice

(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, WW Sales & Marketing

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	201,500	D
Common Stock								1,699	I	The Joseph Roger Sciammas 2020 Irrevocable Trust
Common Stock								2,000	I	Rosalind Sciammas Family 2021 Trust
Common Stock								1,299	I	Rosalind Sciammas Brokerage Account
Common Stock								49,460	I	Sciammas Family Trust
Common Stock								26,660	I	Various Sciammas GRATs
Common Stock								1,699	I	The Patrick Francis Sciammas 2020 Irrevocable Trust
Common Stock								4,015	I	By Sciammas Trust 2020
Common Stock								5,000	I	Clement Sciammas Family 2021 Trust
Common Stock								1,000	I	Peter Rafferty and Eric Toothill 2021Trust
Common Stock								1,699	I	The Chloe Liliane Sciammas 2020 Irrevocable Trust
Common Stock								1,499	I	Clement Sciammas 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. 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, attorney-in-fact for Mr. Maurice Sciammas	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 EVP Maurice Sciammas report?

Maurice Sciammas reported an award of 57,170 MPWR common shares. These shares were issued on February 3, 2026 after performance-based restricted stock units vested and were certified by the Compensation Committee, and were received at a price of $0 per share.

How many Monolithic Power Systems (MPWR) shares does Maurice Sciammas now hold directly?

After the reported transaction, Maurice Sciammas directly holds 201,500 MPWR common shares. This figure reflects the addition of 57,170 fully vested shares awarded on February 3, 2026, following satisfaction of performance conditions on previously granted PSUs.

What triggered the 57,170-share award to MPWR executive Maurice Sciammas?

The 57,170-share award was triggered when performance criteria for PSUs granted on February 7, 2023 were certified as achieved. On February 3, 2026, the Compensation Committee approved the results, causing the PSUs to convert into fully vested common shares for Sciammas.

Were the 57,170 MPWR shares granted to Maurice Sciammas subject to vesting?

All 57,170 shares granted to Maurice Sciammas fully vested on February 3, 2026. They were released the same day after the Compensation Committee certified achievement of the three-year performance conditions tied to the original February 7, 2023 PSU grant.

At what price were the 57,170 MPWR shares granted to Maurice Sciammas?

The 57,170 MPWR common shares were granted to Maurice Sciammas at a price of $0 per share. This reflects a conversion of performance-based restricted stock units into fully vested stock, subject to tax withholdings under the terms of the grant agreement.

What indirect MPWR shareholdings related to Maurice Sciammas are disclosed?

Indirect MPWR holdings are disclosed across several entities, including the Sciammas Family Trust and multiple 2020 and 2021 family or irrevocable trusts. Each line lists the number of common shares held, such as 49,460 shares in the Sciammas Family Trust and 26,660 in various GRATs.