Monolithic Power SEC Filings

Form 144 filing for Monolithic Power Systems, Inc. (MPWR). The notice reports a proposed sale of 4,000 shares of Common Stock on the NASDAQ with an aggregate market value of $3,386,844.86 and approximately 47,904,694 shares outstanding. The proposed approximate sale date is 08/29/2025, and the broker listed is Luzerner Kantonalbank AG, Pilatusstrasse 12, Luzern. The securities to be sold were acquired as Restricted Stock Units from the issuer on 10/23/2013 (2,500 shares) and 10/23/2014 (1,500 shares). The filer reports no securities sold by the person in the past three months. The filing includes the standard seller representation regarding material nonpublic information and a signature/attestation statement.

Jeff Zhou, a director of Monolithic Power Systems, Inc. (MPWR), reported an open-market sale of company stock. On 08/27/2025 he disposed of 193 shares at a reported price of $870 per share, and after the transaction he directly beneficially owned 5,611 shares. The Form 4 indicates the filing was submitted by one reporting person and signed by an attorney-in-fact on behalf of Mr. Zhou.

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.

Monolithic Power Systems (MPWR) filed a Form 144 to notify a proposed sale of 1,499 shares of common stock through UBS Financial Services Inc. on 08/22/2025 on the NASDAQ. The filing shows an aggregate market value of 1,229,180 and reports 49,780,000 shares outstanding. The shares were received via GRAT distributions on 08/19/2025 from Maurice Sciammas in three lots of 669, 81, and 749 shares with related acquisition dates and prior donor acquisition dates noted. The filer reports no securities sold by the person in the past three months and certifies there is no undisclosed material adverse information about the issuer.

Monolithic Power Systems (MPWR) Form 4 summary: On 08/19/2025 Maurice Sciammas, EVP, Worldwide Sales & Marketing and trustee for multiple family trusts, reported several non‑sale transfers of MPWR common stock among trust and brokerage accounts. The filing shows a distribution of 1,000 shares from the Peter Rafferty and Eric Toothill 2021 Irrevocable Trust to an unrelated individual and 1,499 shares moved from Sciammas Siblings 2021 GRATs to the Rosalind Sciammas brokerage account, with a corresponding receipt of 1,499 shares into that brokerage account. The filing states no funds were exchanged for these transfers and that the reporting person lacks management, investment control or pecuniary interest over the 1,000‑share distribution.

Monolithic Power Systems (MPWR) Form 4 shows insider sales by Michael R. Hsing, who is listed as CEO and a director. On 08/15/2025 the reporting person, via an attorney-in-fact, sold multiple blocks of common stock in separate transactions totaling 20,231 shares. The reported sale prices per line are weighted averages ranging from about $825.06 to $836.50. After these transactions the filings show direct beneficial ownership levels on each line declining to a final reported direct holding of 814,667 shares. The filing also discloses indirect holdings of 133,040 shares held by the M Hsing 04 Trust and 12,825 shares held by the ZH Family 2020 Trust. The Form 4 is signed by an attorney-in-fact for Mr. Hsing and provides weighted-average price ranges for each sale line.

Form 144 notice from an insider of Monolithic Power Systems, Inc. (MPWR) reports a proposed sale of common stock. The filing names Morgan Stanley Smith Barney LLC as broker and lists 20,231 shares planned for sale on 08/15/2025 on the NASDAQ with an aggregate market value of $16,773,556.49. The shares were acquired as performance shares from the issuer on 01/01/2024. The filer reports 47,892,000 shares outstanding for the class and indicates no securities sold by the filer in the past three months. The notice includes the standard certification that the seller is not aware of undisclosed material adverse information and references Rule 10b5-1 plan language but does not state a plan adoption date.

Monolithic Power Systems director Jeff Zhou reported a sale of 400 shares of the company's common stock on 08/13/2025 at a price of $850 per share. After the reported transaction, Mr. Zhou beneficially owned 5,804 shares. The Form 4 was signed by an attorney-in-fact on behalf of Mr. Zhou.

Jeff Zhou, a director of Monolithic Power Systems, Inc. (MPWR), reported a transaction on 08/12/2025. The Form 4 shows a Transaction Code: S on common stock with a reported quantity of 200 shares and a price listed as $830. Following the reported transaction the filing shows 6,204 shares beneficially owned in a direct form. The form was signed by attorney-in-fact Saria Tseng on 08/12/2025.