Insider plans 33,000-share MPWR Rule 144 sale

Michael Hsing filed a notice of proposed sale under Rule 144 covering 33,000 shares of Common Stock of MPWR through Morgan Stanley Smith Barney LLC on NASDAQ, with an aggregate market value of 38,670,192.00.

Rhea-AI Filing Summary

Michael Hsing filed a notice of proposed sale under Rule 144 covering 33,000 shares of Common Stock of MPWR through Morgan Stanley Smith Barney LLC on NASDAQ, with an aggregate market value of 38,670,192.00.

The shares to be sold were acquired as performance shares from the issuer on 02/03/2026 and 10/25/2025, totaling 14,902 and 18,098 shares. Common shares outstanding were 47,907,000. During the past three months, Hsing sold 33,000, 34,000, and 54,923 common shares for gross proceeds of 39,234,171.90, 38,837,373.80, and 64,323,823.90, respectively.

FAQ

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

What does Michael Hsing’s Form 144 filing for MPWR disclose?

The filing discloses that Michael Hsing plans to sell 33,000 MPWR common shares under Rule 144. The planned sale has an aggregate market value of about $38.67 million and will be executed through Morgan Stanley Smith Barney LLC on the NASDAQ exchange.

How many MPWR shares is Michael Hsing proposing to sell under Rule 144?

He is proposing to sell 33,000 shares of MPWR common stock. These shares are associated with performance share awards acquired from the issuer on February 3, 2026 and October 25, 2025, and are to be sold through a broker on NASDAQ.

What were the recent MPWR stock sales by Michael Hsing in the last three months?

In the last three months, Michael Hsing sold 33,000, 34,000, and 54,923 MPWR common shares. These transactions generated gross proceeds of approximately $39.23 million, $38.84 million, and $64.32 million, respectively, according to the Rule 144 disclosure.

How many MPWR shares are outstanding in this Form 144 disclosure?

The disclosure lists 47,907,000 MPWR common shares outstanding. This figure provides context for the size of the planned 33,000-share sale and past sales reported over the previous three months under Rule 144.

How did Michael Hsing acquire the MPWR shares being registered for sale?

The shares being registered for sale were acquired as performance shares directly from the issuer. They were obtained on February 3, 2026 and October 25, 2025, with the filing indicating the nature of acquisition transaction as performance share grants.

Which broker will handle Michael Hsing’s planned MPWR stock sale?

Morgan Stanley Smith Barney LLC Executive Financial Services will handle the planned MPWR stock sale. The broker’s listed office is at 1 New York Plaza, 8th Floor, New York, NY 10004, and the shares are to be sold on the NASDAQ exchange.

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

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Accepted by SEC EDGAR 02/12/2026 - 04:26 PM 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	0001308676
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	(425) 296-9956
Name of Person for Whose Account the Securities are To Be Sold	MICHAEL HSING
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
Relationship to Issuer	Director

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	33000	38670192.00	47907000	02/12/2026	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	02/03/2026	Performance Shares	ISSUER			14902	02/03/2026	Not Applicable
Common	10/25/2025	Performance Shares	ISSUER			18098	10/25/2025	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
MICHAEL HSING 1555 Palm Beach Lakes Blvd. West Palm Beach FL 33401	Common	02/11/2026	33000	39234171.90
MICHAEL HSING 1555 Palm Beach Lakes Blvd. West Palm Beach FL 33401	Common	02/10/2026	34000	38837373.80
Michael Hsing 1555 Palm Beach Lakes Blvd. West Palm Beach FL 33401	Common	02/06/2026	54923	64323823.90

144: Remarks and Signature

Remarks
Date of Notice	02/12/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	08/28/2025
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/ Michael Hsing
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)