Large insider plans $60.4M Rule 144 stock sale in MPWR (MPWR)

Rhea-AI Filing Summary

An affiliated seller has filed a notice of proposed sale under Rule 144 to dispose of 51,841 shares of common stock through Morgan Stanley Smith Barney, with an indicated aggregate market value of $60,385,952.03. The planned sale is listed for execution on February 4, 2026 on the NASDAQ exchange.

The shares to be sold were acquired on February 3, 2026 as performance-based restricted stock units from the issuer. The filing also reports that Michael Hsing sold 40,000 and 30,000 shares of common stock in two prior transactions on November 11 and 12, 2025, for gross proceeds of $38,335,600.00 and $28,958,700.00, respectively.

Insights

Equity markets and insider-transactions analyst

Large planned Rule 144 insider sale, but mechanistic and disclosed.

The notice describes a planned Rule 144 sale of 51,841 common shares with an aggregate market value of $60,385,952.03. The shares come from performance-based restricted stock units acquired on February 3, 2026, suggesting equity compensation vesting rather than an open‑market purchase.

The form also lists earlier sales by Michael Hsing over the prior three months totaling 70,000 shares and gross proceeds of about $67.3M. All transactions are routed through a major broker and disclosed under Rule 144, which provides a structured framework for affiliate sales. The filing itself does not state any change in the issuer’s operations; the impact depends on how the market interprets insider selling.

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

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	51841	60385952.03	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			51841	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
Michael Hsing 1555 PALM BEACH LAKES BLVD. WEST PALM BEACH FL 98033	Common Stock	11/11/2025	40000	38335600.00
Michael Hsing 1555 PALM BEACH LAKES BLVD. WEST PALM BEACH FL 98033	Common Stock	11/12/2025	30000	28958700.00

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

How many MPWR shares are planned to be sold in this Rule 144 filing?

The notice covers a proposed sale of 51,841 shares of common stock. These shares are to be sold through Morgan Stanley Smith Barney, with an indicated aggregate market value of $60,385,952.03 and an approximate sale date of February 4, 2026.

What is the aggregate market value of the MPWR shares in this planned sale?

The filing lists an aggregate market value of $60,385,952.03 for the 51,841 common shares to be sold. This figure reflects the market valuation used in the Rule 144 notice for the planned NASDAQ transaction on February 4, 2026.

How and when were the MPWR shares in this Form 144 acquired?

The shares in this notice were acquired on February 3, 2026 as performance-based restricted stock units from the issuer. The amount acquired was 51,841 common shares, and the filing indicates “N/A” for the nature of payment, consistent with equity-based compensation.

What prior MPWR stock sales by the filer are disclosed in the past three months?

The document reports that Michael Hsing sold 40,000 shares on November 11, 2025 for $38,335,600.00 and 30,000 shares on November 12, 2025 for $28,958,700.00. Both transactions involved common stock and are listed as prior three‑month sales.

Which broker is handling the proposed MPWR Rule 144 share sale?

The proposed sale is to be executed through Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, 8th Floor, New York, FL 10004. The filing specifies NASDAQ as the securities exchange for this common stock transaction.

What representation does the seller make about MPWR’s information in this notice?

By signing the notice, the seller represents that they do not know any material adverse information about the issuer’s current or prospective operations that has not been publicly disclosed, consistent with the certification language included in the Rule 144 form.