STOCK TITAN

EVP at Monolithic Power (MPWR) sells 30 shares under 10b5-1 plan

Filing Impact
(Neutral)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Monolithic Power Systems EVP Maurice Sciammas, through the Clement Sciammas Trust, sold 30 shares of common stock in an open-market transaction at $1,116.44 per share on April 1, 2026.

The trust held 1,239 shares after the sale as indirect ownership. Sciammas also held 178,644 shares directly, while other related trusts and accounts held additional indirect positions, including 49,460 shares in the Sciammas Family Trust and 26,660 shares in various Sciammas GRATs. The sale was made under a Rule 10b5-1 trading plan adopted on November 19, 2025.

Positive

  • None.

Negative

  • None.
Insider Sciammas Maurice
Role EVP, WW Sales & Marketing
Sold 30 shs ($33K)
Type Security Shares Price Value
Sale Common Stock 30 $1,116.44 $33K
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 — 1,239 shares (Indirect, Clement Sciammas Trust); Common Stock — 178,644 shares (Direct)
Footnotes (1)
  1. [object Object]
Shares sold 30 shares Open-market sale on April 1, 2026 via Clement Sciammas Trust
Sale price per share $1,116.44 per share Common stock sale on April 1, 2026
Trust holdings after sale 1,239 shares Clement Sciammas Trust indirect ownership following transaction
Direct holdings 178,644 shares Direct common stock position of Maurice Sciammas after transaction
Sciammas Family Trust holdings 49,460 shares Indirect holdings in Sciammas Family Trust
Various Sciammas GRATs holdings 26,660 shares Indirect holdings in various Sciammas GRATs
Rule 10b5-1 trading plan regulatory
"These transactions were made pursuant to a Rule 10b5-1 trading plan adopted on 11/19/2025."
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
open-market sale financial
"transaction_action: "open-market sale" for the 30-share transaction."
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
"ownership_type: "indirect" and nature_of_ownership: "Clement Sciammas Trust"."
GRATs financial
"nature_of_ownership: "Various Sciammas GRATs" for one indirect holding entry."
Form 4 regulatory
"INSIDER FILING DATA (Form 4) describing the reported transactions."
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).
X
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)
04/01/2026
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 Stock04/01/2026S30(1)D$1,116.441,239IClement Sciammas Trust
Common Stock1,699IThe Joseph Roger Sciammas 2020 Irrevocable Trust
Common Stock2,000IRosalind Sciammas Family 2021 Trust
Common Stock1,299IRosalind Sciammas Brokerage Account
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 Stock5,000IClement Sciammas Family 2021 Trust
Common Stock49,460ISciammas Family 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:
1. These transactions were made pursuant to a Rule 10b5-1 trading plan adopted on 11/19/2025.
Remarks:
/s/ Saria Tseng, attorney-in-fact for Mr. Maurice Sciammas04/03/2026
** 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 open-market sale of 30 MPWR shares. The sale was executed at $1,116.44 per share through the Clement Sciammas Trust, leaving that trust with 1,239 shares of Monolithic Power Systems common stock as indirect ownership.

At what price were the MPWR shares sold in this Form 4 filing?

The reported MPWR shares were sold at $1,116.44 per share. This open-market transaction involved 30 shares of Monolithic Power Systems common stock and was executed through the Clement Sciammas Trust, an indirect ownership vehicle associated with executive Maurice Sciammas.

How many Monolithic Power Systems (MPWR) shares does Maurice Sciammas hold directly after the transaction?

After the reported transaction, Maurice Sciammas directly held 178,644 MPWR shares. In addition to this direct position, multiple trusts and related accounts held further indirect positions in Monolithic Power Systems common stock as of the same date.

Was the MPWR insider sale made under a Rule 10b5-1 trading plan?

Yes, the insider sale was made under a Rule 10b5-1 trading plan. The filing notes that the transactions were executed pursuant to a pre-arranged plan adopted on November 19, 2025, indicating the trades were scheduled in advance rather than timed discretionarily.

Which trust executed the 30-share sale of MPWR stock?

The 30-share sale of MPWR stock was executed by the Clement Sciammas Trust. This entity is reported as holding the shares indirectly for executive Maurice Sciammas and retained 1,239 shares of Monolithic Power Systems common stock after the transaction.