MONOLITHIC POWER SYSTEMS INC SEC Filing

Saria Tseng submitted a Form 144 notice relating to proposed sales of Common stock, listing 25,674 shares tied to Performance Shares with an original grant date of 08/07/2021.

Rhea-AI Filing Summary

Saria Tseng submitted a Form 144 notice relating to proposed sales of Common stock, listing 25,674 shares tied to Performance Shares with an original grant date of 08/07/2021. The filing also records a reported sale of 22,876 shares on 02/06/2026.

Key Figures

Proposed shares to be sold: 25,674 shares Shares sold during past 3 months: 22,876 shares Reported dollar figure: 25943648.15 +2 more

5 metrics

Proposed shares to be sold 25,674 shares Performance Shares grant date 08/07/2021

Shares sold during past 3 months 22,876 shares Sale date 02/06/2026 by Saria Tseng

Reported dollar figure 25943648.15 Value string present in securities information row

Data reference date 03/30/2026 Date appearing in securities information row

Large numeric field present 49,118,000 Numeric value included in the securities information row

Key Terms

Form 144, Performance Shares, Common, Securities To Be Sold

4 terms

Form 144 regulatory

"Form type shown as 144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Performance Shares financial

"Performance Shares | ISSUER | 08/07/2021"

Performance shares are a type of company stock given to executives or employees that only become theirs if the company meets specific goals, like hitting certain profits or growth targets. They motivate leaders to work toward the company’s success, because their additional shares depend on achieving these results.

Common financial

"Common | Morgan Stanley Smith Barney LLC Executive Financial Services"

Securities To Be Sold regulatory

"144: Securities To Be Sold | Common | 08/07/2021"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the MPWR Form 144 disclose about the shares to be sold?

The Form 144 lists a proposed sale of 25,674 shares of Common stock tied to Performance Shares dated 08/07/2021. The filing identifies the security type as Common and references the grant date for those Performance Shares.

Did the filing report any recent sales for MPWR insiders?

Yes; the filing records a sale by Saria Tseng of 22,876 shares on 02/06/2026. That sale is shown separately from the proposed 25,674-share notice included in the Form 144 excerpt.

Who is listed as the broker or dealer handling the transaction in the MPWR filing?

The broker listed is Morgan Stanley Smith Barney LLC Executive Financial Services at 1 New York Plaza. That broker entry appears in the securities information section of the Form 144 excerpt.

What grant date and security type are associated with the shares in this MPWR Form 144?

The shares are identified as Performance Shares with a grant/origin date of 08/07/2021, and the security class is listed as Common stock in the filing excerpt.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 03/30/2026 - 05:58 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001312593
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	MONOLITHIC POWER SYSTEMS, INC.
SEC File Number	000-51026
Address of Issuer	1555 Palm Beach Lakes Blvd. West Palm Beach FLORIDA 33401
Phone	(561) 839-3999
Name of Person for Whose Account the Securities are To Be Sold	SARIA TSENG
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	25674	25943648.15	49118000	03/30/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/07/2021	Performance Shares	ISSUER			25674	08/07/2021	Not Applicable

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
SARIA TSENG 1555 Palm Beach Lakes Blvd. West Palm Beach FL 33401	Common	02/06/2026	22876	26791540.80

144: Remarks and Signature

Remarks	The securities to be sold were acquired upon the vesting of performance shares during the period of 8/7/2021 through 5/7/2023.
Date of Notice	03/30/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	11/28/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Saria Tseng
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)