STOCK TITAN

Monolithic Power (MPWR) EVP logs 380-share indirect sale, retains stake

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Monolithic Power Systems EVP Maurice Sciammas reported an indirect open-market sale of 380 shares of common stock at $1,583.81 per share through the Rosalind Sciammas Brokerage Account on May 5, 2026, leaving 919 shares in that account. The filing also lists multiple indirect trust and GRAT holdings and shows a separate direct holding of 178,644 common shares as of the same date.

Positive

  • None.

Negative

  • None.
Insider Sciammas Maurice
Role EVP, WW Sales & Marketing
Sold 380 shs ($602K)
Type Security Shares Price Value
Sale Common Stock 380 $1,583.81 $602K
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
Holdings After Transaction: Common Stock — 919 shares (Indirect, Rosalind Sciammas Brokerage Account); Common Stock — 178,644 shares (Direct, null)
Footnotes (1)
Shares sold 380 shares Open-market sale of common stock on May 5, 2026
Sale price per share $1,583.81 per share Price for 380 MPWR shares sold indirectly
Shares remaining in brokerage account 919 shares Rosalind Sciammas Brokerage Account after sale
Direct common shares 178,644 shares Direct holding of Maurice Sciammas as of May 5, 2026
Sciammas Family Trust holding 49,460 shares Indirect common stock held by Sciammas Family Trust
Various Sciammas GRATs holding 26,660 shares Indirect common stock held by Various Sciammas GRATs
open-market sale financial
"Transaction code S indicates an open-market sale of common stock"
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
indirect ownership financial
"The sale occurred through an account reported as indirect ownership"
trust financial
"Several entries list common stock held through various Sciammas trusts"
GRATs financial
"One holding entry is described as held by Various Sciammas GRATs"
Form 4 regulatory
"The insider transaction is disclosed in a Form 4 filing"
Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.
SEC Form 4
FORM 4UNITED 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 FLORIDA 33401

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
MONOLITHIC POWER SYSTEMS INC [ MPWR ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
EVP, WW Sales & Marketing
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/05/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
CodeVAmount(A) or (D)Price
Common Stock178,644D
Common Stock05/05/2026S380D$1,583.81919IRosalind Sciammas Brokerage Account
Common Stock1,699IThe Joseph Roger Sciammas 2020 Irrevocable Trust
Common Stock2,000IRosalind Sciammas Family 2021 Trust
Common Stock49,460ISciammas Family Trust
Common Stock26,660IVarious Sciammas GRATs
Common Stock1,699IThe Patrick Francis Sciammas 2020 Irrevocable Trust
Common Stock4,015IBy Sciammas Trust 2020
Common Stock1,000IPeter Rafferty and Eric Toothill 2021Trust
Common Stock1,699IThe Chloe Liliane Sciammas 2020 Irrevocable Trust
Common Stock1,209IClement Sciammas Trust
Common Stock5,000IClement 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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
Remarks:
/s/ Saria Tseng, attorney-in-fact for Mr. Maurice Sciammas05/06/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did MPWR executive Maurice Sciammas report?

Maurice Sciammas reported an indirect open-market sale of 380 Monolithic Power Systems shares at $1,583.81 per share. The transaction was executed through the Rosalind Sciammas Brokerage Account and is classified as a sale of common stock in a Form 4 filing.

How many MPWR shares did Maurice Sciammas sell and at what price?

He sold 380 shares of Monolithic Power Systems common stock at $1,583.81 per share. This was an indirect open-market transaction reported under code S, reflecting a routine share sale rather than a grant, option exercise, or tax-withholding event.

What are Maurice Sciammas’ remaining holdings after this MPWR sale?

After the sale, the Rosalind Sciammas Brokerage Account held 919 MPWR shares. The Form 4 also shows a separate direct holding of 178,644 common shares, along with several indirect positions held through various Sciammas family trusts and GRATs as of the transaction date.

Is the MPWR sale by Maurice Sciammas a direct or indirect holding change?

The 380-share sale was from an indirect holding in the Rosalind Sciammas Brokerage Account. In addition to this indirect position, the Form 4 lists multiple indirect trust holdings and a substantial direct holding of 178,644 Monolithic Power Systems common shares for Maurice Sciammas.

What type of Form 4 activity is reported for MPWR in this filing?

The Form 4 for Monolithic Power Systems reports primarily holding entries plus one open-market sale of 380 common shares. Most entries reflect updated direct and indirect share balances in trusts and accounts associated with Maurice Sciammas, rather than new grants or option exercises.