Insider plans sale of 21,590 shares in MPWR (NASDAQ: MPWR)

Rhea-AI Filing Summary

This Form 144 notice relates to a planned sale of up to 21,590 shares of common stock through Morgan Stanley Smith Barney LLC on the NASDAQ, with an indicated aggregate market value of $25,148,679.70. The issuer has 48,710,953 shares outstanding.

The seller, Saria Tseng, acquired these 21,590 shares on February 3, 2026 as performance-based restricted stock units from the issuer. Over the prior three months, the filing lists additional sales by Saria Tseng totaling 40,000 shares of common stock on November 25 and 26, 2025, with gross proceeds of $18,083,600.00 and $18,529,300.00, respectively.

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

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

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

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 Stock	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York FL 10004	21590	25148679.70	48710953	02/04/2026	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 Stock	02/03/2026	Performance-based restricted stock units	Issuer			21590	02/03/2026	N/A

* 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 98033	Common Stock	11/25/2025	20000	18083600.00
SARIA TSENG 1555 PALM BEACH LAKES BLVD. WEST PALM BEACH FL 98033	Common Stock	11/26/2025	20000	18529300.00

144: Remarks and Signature

Remarks

Date of Notice

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

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What does the MPWR Form 144 filing disclose about planned share sales?

The filing discloses a planned sale of 21,590 common shares. These shares, valued in total at $25,148,679.70, are to be sold on NASDAQ through Morgan Stanley Smith Barney LLC under Rule 144 resale provisions for restricted or controlled securities.

Who is the selling security holder in this MPWR Form 144 notice?

The selling security holder listed is Saria Tseng. The filing identifies her as the person for whose account 21,590 common shares are to be sold and also lists her as the seller in prior sales over the past three months.

How and when were the 21,590 MPWR shares to be sold acquired?

The 21,590 shares were acquired on February 3, 2026. They were obtained from the issuer as performance-based restricted stock units, with the acquisition date and the payment date both shown as February 3, 2026 in the filing.

What prior MPWR share sales by the same holder does the Form 144 list?

The notice lists two prior sales totaling 40,000 shares. Saria Tseng sold 20,000 common shares on November 25, 2025 and another 20,000 on November 26, 2025, with gross proceeds of $18,083,600.00 and $18,529,300.00, respectively.

On which exchange are the MPWR shares in this Form 144 expected to be sold?

The planned sales are identified for the NASDAQ market. The securities information section specifies that the 21,590 common shares covered by this notice are intended to be sold on NASDAQ, using Morgan Stanley Smith Barney LLC as the broker.

How many MPWR shares are reported as outstanding in the Form 144 filing?

The filing reports 48,710,953 shares outstanding. This figure is shown alongside the 21,590 common shares covered by the notice, providing context on the issuer’s total common stock outstanding at the time of the planned Rule 144 sale.