Monolithic Power (MPWR) Form 144 Shows Recent Insider Sales and Proposed 193-Share Sale

Rhea-AI Filing Summary

Form 144 filing for Monolithic Power Systems (MPWR) reports a proposed sale of 193 common shares through Morgan Stanley Smith Barney LLC on 08/27/2025. The filer discloses three prior restricted-stock acquisitions (48 shares on 02/12/2021; 133 shares on 02/02/2022; 12 shares on 02/08/2023) and two recent open-market sales by the same person: 400 shares sold 08/13/2025 for $340,000 and 200 shares sold 08/12/2025 for $166,000. The filing includes the broker, share counts, aggregate market value for the proposed sale ($167,910), and the statement that the filer is not aware of undisclosed material adverse information.

Positive

• Required disclosures provided: broker, proposed sale date, share counts, and aggregate market value are all specified
• Recent transaction history included, showing prior sales and acquisition dates which improves transparency

Negative

• No disclosure of total insider ownership percentage, limiting assessment of how significant the sales are relative to holdings
• No explicit statement of a 10b5-1 trading plan, so it is unclear whether sales are pre-arranged or opportunistic

Insights

Financial Analyst

TL;DR: Insider disclosed small open-market sales and a proposed sale; activity is transparent but not clearly material to company fundamentals.

The filing documents routine insider liquidity: three acquisitions were restricted stock grants dated 2021–2023 and recent sales of 600 shares generated $506,000 in gross proceeds across two trades. The new proposed sale of 193 shares has an indicated aggregate market value of $167,910 and will be executed through Morgan Stanley Smith Barney. This disclosure allows investors to track insider selling activity but contains no information about company performance, earnings, or changes to governance. Absent additional context on total insider holdings or percentage ownership, the filing is primarily a compliance disclosure rather than a signal of material corporate change.

Corporate Governance Expert

TL;DR: Filing meets Rule 144 disclosure requirements; shows recent insider sales but provides no indication of impropriety or governance issues.

The notice lists the broker, planned sale date, and prior acquisitions and sales, and includes the required representation about lack of undisclosed material information. From a governance perspective, the form is complete for a Rule 144 notice. It does not include details on total insider ownership percentages or whether sales are part of a pre-established trading plan; the filer represents compliance but does not state a 10b5-1 plan. As filed, the document raises standard transparency points but not governance red flags on its face.

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	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	193	167910.00	47892000	08/27/2025	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	02/02/2022	Restricted Stock	ISSUER			133	02/02/2022	Not Applicable
Common	02/08/2023	Restricted Stock	ISSUER			12	02/08/2023	Not Applicable
Common	02/12/2021	Restricted Stock	ISSUER			48	02/12/2021	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
JEFF ZHOU 5808 Lake Washington Blvd. NE Kirkland WA 98033	Common	08/13/2025	400	340000.00
JEFF ZHOU 5808 Lake Washington Blvd. NE Kirkland WA 98033	Common	08/12/2025	200	166000.00

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 filed on behalf of Jeff Zhou disclose?

The filing discloses a proposed sale of 193 common shares via Morgan Stanley on 08/27/2025, prior restricted-stock acquisitions (48, 133, and 12 shares), and recent sales of 400 shares (08/13/2025) for $340,000 and 200 shares (08/12/2025) for $166,000.

Who is the broker handling the proposed MPWR sale?

The proposed sale is to be handled by Morgan Stanley Smith Barney LLC, Executive Financial Services, 1 New York Plaza, 8th Floor, New York, NY.

How much aggregate market value is reported for the proposed sale of MPWR shares?

The filing reports an aggregate market value of $167,910 for the proposed sale of 193 shares.

What recent sales by the filer are included in the Form 144?

The filer sold 400 shares on 08/13/2025 for $340,000 and 200 shares on 08/12/2025 for $166,000.

Does the Form 144 state whether a 10b5-1 trading plan was used?

The filing does not state that a 10b5-1 plan was adopted; it only includes the standard representation about knowledge of undisclosed material information.