Monolithic Power SEC Filings

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.

Monolithic Power Systems (MPWR) Form 144 shows a planned sale of 400 common shares through Morgan Stanley Smith Barney LLC on NASDAQ, with an aggregate market value of $340,000. The filing reports 47,892,000 shares outstanding, so the 400-share sale represents roughly 0.0008% of the companys outstanding stock.

The securities to be sold were acquired as restricted stock on 02/07/2024 (270 shares) and 02/08/2023 (130 shares). The notice also lists a prior sale by JEFF ZHOU of 200 shares on 08/12/2025 for gross proceeds of $166,000. The document includes the standard representation that the seller is not aware of undisclosed material adverse information about the issuer.

Monolithic Power Systems, Inc. (MPWR) filed a Form 144 reporting a proposed sale of 200 shares of common stock acquired as restricted stock on 02/07/2024. The filing lists an aggregate market value of $166,000 for the shares and shows 47,892,000 shares outstanding. The sale is to be effected through Morgan Stanley Smith Barney LLC on NASDAQ with an approximate sale date of 08/12/2025. The filer reports no sales in the past three months and makes the required statement that they are not aware of undisclosed material adverse information about the issuer.

Xiao Deming, identified as EVP, Global Operations of Monolithic Power Systems, reported an internal transfer of company common stock on Form 4. The filing shows 945 shares were moved from Mr. Xiao's direct holdings into the Christopher Chao Xiao Trust and the form states explicitly that no funds were exchanged.

Following the reported transaction the Form 4 lists 120,660 shares beneficially owned directly by the reporting person, 4,336 shares beneficially owned indirectly by the Christopher Chao Xiao Trust, and 20,455 shares held indirectly by a spouse.

Transaction overview: On 08/06/2025, Maurice Sciammas, EVP, WW Sales & Marketing of Monolithic Power Systems Inc. (MPWR), filed a Form 4 reporting non‑derivative transactions in MPWR common stock involving intra‑family trust transfers.

The filing reports transfers of 4,836 shares to the Sciammas Family Trust and transfers of 2,000, 1,418 and 1,418 shares from various Sciammas 2022 GRATs and 2022 Trusts for Oski Crew into the Sciammas Family Trust. The filing states no funds were exchanged and no sale occurred for those transfers. The Sciammas Family Trust is reported to beneficially own 44,930 shares following the reported transaction(s); other trusts show beneficial ownership figures of 13,727, 9,481 and 9,481 in the filing.

The form is signed by Saria Tseng as attorney‑in‑fact for Mr. Sciammas on 08/06/2025. No derivative transactions, option exercises or cash sales are reported in this filing.