Monolithic Power (MPWR) EVP sells shares to cover RSU taxes

Rhea-AI Filing Summary

Monolithic Power Systems executive Maurice Sciammas, EVP, WW Sales & Marketing, reported selling 22,875 shares of common stock on 02/06/2026 at $1,171.1637 per share. The sale, coded "S", was made to cover taxes due upon the release of restricted stock units, as required by the company’s equity incentive plan.

Following this tax-related sale, he directly holds 178,625 common shares and also has additional indirect holdings through various family trusts and brokerage 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

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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^*

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)
02/06/2026

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	02/06/2026		S		22,875(1)	D	$1,171.1637	178,625	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								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
Common Stock								5,000	I	Clement Sciammas Family 2021 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 sales were to cover taxes upon the release of restricted stock units, as required by the Company's equity incentive plan.

Remarks:

	/s/ Saria Tseng, attorney-in-fact for Mr. Maurice Sciammas	02/10/2026
	** 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 executive Maurice Sciammas report?

Maurice Sciammas reported selling 22,875 shares of Monolithic Power Systems common stock. The transaction occurred on February 6, 2026, at $1,171.1637 per share and was coded as a sale, according to the Form 4 insider trading report.

Why did MPWR EVP Maurice Sciammas sell 22,875 shares?

The 22,875 shares sold by Maurice Sciammas were to cover taxes upon the release of restricted stock units. This was required under Monolithic Power Systems’ equity incentive plan, meaning the transaction was driven by tax withholding rather than a discretionary open-market sale.

How many MPWR shares does Maurice Sciammas own after this Form 4 transaction?

After the reported tax-related sale, Maurice Sciammas directly owns 178,625 shares of Monolithic Power Systems common stock. In addition, Form 4 lists multiple indirect holdings through family trusts and related accounts that hold further MPWR shares on an indirect basis.

What role does Maurice Sciammas hold at Monolithic Power Systems (MPWR)?

Maurice Sciammas serves as Executive Vice President, Worldwide Sales & Marketing at Monolithic Power Systems. His position as a senior officer makes him a Section 16 reporting person, requiring prompt disclosure of his transactions in MPWR stock on Form 4 filings.

Were the MPWR shares sold by Maurice Sciammas held directly or indirectly?

The 22,875 MPWR shares sold on February 6, 2026 were held directly by Maurice Sciammas. The Form 4 also lists several indirect holdings in Monolithic Power Systems stock through multiple family trusts and related accounts that remain after the reported transaction.

What indirect MPWR share holdings are associated with Maurice Sciammas?

Indirect MPWR holdings associated with Maurice Sciammas include shares held by entities such as the Sciammas Family Trust, various Sciammas GRATs, multiple 2020 irrevocable trusts, family 2021 trusts, and brokerage or family accounts, each reported with its own share balance on Form 4.