MPWR files Form 144 for proposed insider common‑stock sales

MPWR submitted a Form 144 notice reporting proposed sales of Common Stock by insiders.

Rhea-AI Filing Summary

MPWR submitted a Form 144 notice reporting proposed sales of Common Stock by insiders. The filing lists transaction dates of 05/18/2026, 05/22/2026, and an entry dated 05/26/2026, and identifies Robert Dean in connection with a common-stock entry.

Insights

Securities Compliance Analyst

Routine Form 144 sale notice; procedural disclosure rather than a trade execution.

The filing lists proposed sales of Common Stock on specific dates and names a reporting person, Robert Dean. Form 144 is a notice of intent to sell by affiliates and does not itself evidence completion of a sale.

Timing and cash‑flow treatment are not detailed in the excerpt; subsequent Form 4 or broker records would show executed transactions.

Key Figures

Filing dates listed: 05/18/2026; 05/22/2026; 05/26/2026 Numeric entry: 35,882.23 Numeric entry: 49,141,959 +1 more

4 metrics

Filing dates listed 05/18/2026; 05/22/2026; 05/26/2026 Dates associated with securities entries in the excerpt

Numeric entry 35,882.23 Value appearing on the securities line near NASDAQ entry

Numeric entry 49,141,959 Value appearing on the same line as 35,882.23 in the excerpt

Robert Dean line amount 6,253.12 Numeric value shown on Robert Dean's common-stock line dated 05/18/2026

Key Terms

Form 144, Time-based restricted stock units, Issuer

3 terms

Form 144 regulatory

"submitted a Form 144 notice regarding proposed sales of Common Stock"

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.

Time-based restricted stock units financial

"Time-based restricted stock units | Issuer | 05/22/2026"

Time-based restricted stock units are a form of employee compensation where individuals are granted company shares that are earned over a set period, often as a reward for staying with the company. These shares typically become fully owned and transferable only after passing specific time milestones, encouraging long-term commitment. For investors, they highlight a company's focus on employee retention and can influence future stock supply and company stability.

Issuer financial

"Time-based restricted stock units | Issuer"

FAQ

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

What does MPWR's Form 144 filing indicate?

It indicates a notice of proposed sales of Common Stock by insiders. The filing lists specific dates and at least one named reporting person, Robert Dean, but does not confirm executed sales.

Does MPWR's Form 144 mean shares were sold?

No; Form 144 reports intent to sell or offer shares by affiliates. Execution details or completed sales are reported separately, typically on Form 4 or broker confirmations.

Which dates are shown in the MPWR excerpt?

The excerpt includes entries dated 05/18/2026, 05/22/2026, and 05/26/2026. These are the dates associated with the listed securities entries in the notice.

Who is named in the MPWR Form 144 excerpt?

The excerpt names Robert Dean with an associated common-stock line dated 05/18/2026. The filing also references Morgan Stanley Smith Barney LLC as a broker/dealer.

What types of securities are referenced in the filing?

The excerpt references Common Stock and a line showing Time-based restricted stock units as the security class tied to an issuer-related entry dated 05/22/2026.

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

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Accepted by SEC EDGAR 05/26/2026 - 06:50 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	0001445300
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	DEAN ROBERT W II
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 Stock	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	22	35882.23	49141959	05/26/2026	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	05/22/2026	Time-based restricted stock units	Issuer			22	05/22/2026	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
Robert Dean 1555 PALM BEACH LAKES BLVD. WEST PALM BEACH FL 98033	Common Stock	05/18/2026	4	6253.12

144: Remarks and Signature

Remarks
Date of Notice	05/26/2026
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/ Robert Dean
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)