Welcome to our dedicated page for MONOLITHIC POWER SYSTEMS SEC filings (Ticker: MPWR), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Monolithic Power Systems filings document regulatory disclosures for a fabless semiconductor company focused on power electronics solutions. Its 8-K filings furnish quarterly and annual operating results, earnings commentary, cash dividend declarations, officer-transition disclosures, and other material events tied to financial reporting.
The filing record also includes proxy materials covering annual meeting matters, director and executive compensation disclosures, and stockholder voting procedures. Other filings describe governance amendments such as bylaw changes affecting special-meeting rights, and reporting-controls matters including non-reliance determinations and restatement-related disclosures for previously issued financial statements.
Monolithic Power Systems (MPWR) executive Bernie Blegen, EVP and CFO, reported open-market sales of common stock on 11/03/2025 pursuant to a Rule 10b5-1 trading plan adopted on 2/26/2025.
The sales were executed in multiple small lots at weighted average prices, including $1,013.62, $1,019.49, and $1,038.41 per share. Following these transactions, Blegen beneficially owns 74,332 shares directly.
He also reports indirect holdings of 5,331 shares in the Irrevocable Trust FBO Sarah N. Blegen and 5,331 shares in the Irrevocable Trust FBO Theodore F. Blegen.
Monolithic Power Systems (MPWR) — Form 4 insider filing: CEO and Director Michael R. Hsing reported a Code F transaction on 10/30/2025. The filing shows 121,918 shares of common stock were withheld by the company at $1,096.63 per share to satisfy income tax obligations tied to the earnout and vesting of market-based RSUs granted in October 2022.
After the withholding, Hsing beneficially owns 995,669 shares directly. He also has indirect holdings of 133,040 shares through the M Hsing 04 Trust and 12,825 shares through the ZH Family 2020 Trust. Code F indicates a tax-withholding event rather than an open-market sale.
Monolithic Power Systems (MPWR) EVP and CFO Bernie Blegen reported a Form 4 transaction. On 10/30/2025, 48,298 shares of common stock were withheld at $1,096.63 per share to satisfy income taxes related to the earnout and vesting of market-based RSUs granted in October 2022.
Following the transaction, Blegen directly owned 77,332 shares. Indirect holdings include 5,331 shares in an irrevocable trust for Sarah N. Blegen and 5,331 shares in an irrevocable trust for Theodore F. Blegen.
Monolithic Power Systems (MPWR): Form 4 insider transaction
EVP & General Counsel Saria Tseng reported a Code F transaction on 10/30/2025, reflecting tax withholding related to the vesting of market-based RSUs granted in October 2022. The company withheld 54,543 shares of common stock at a price of $1,096.63 per share to satisfy income tax obligations.
Following this withholding, the reporting person directly beneficially owns 207,331 shares of MPWR common stock. Code F indicates shares were disposed of by the issuer solely to cover taxes upon award vesting.
Monolithic Power Systems (MPWR) insider filing: EVP, WW Sales & Marketing Maurice Sciammas reported a Form 4 for a tax-withholding transaction on 10/30/2025. The company withheld 54,543 shares of common stock at $1,096.63 to satisfy income tax obligations tied to the earnout and vesting of market‑based RSUs granted in October 2022.
After the transaction, he holds 183,306 shares directly. Additional indirect holdings are reported across various family trusts and accounts.
Monolithic Power Systems (MPWR) reported an insider tax-withholding transaction by its EVP, Global Operations. On 10/30/2025, the officer had 54,543 shares of common stock withheld at $1,096.63 per share (Form 4 code F) to cover income taxes tied to the earnout and vesting of market-based RSUs granted in October 2022.
After the transaction, the reporting person beneficially owns 201,637 shares directly, plus 20,455 shares held by a spouse and 4,336 shares held by the Christopher Chao Xiao Trust.
Monolithic Power Systems (MPWR) furnished an update on its latest results. The company filed a Form 8‑K to furnish, under Item 2.02, a press release and earnings commentary for the quarter ended September 30, 2025. These materials are provided as Exhibits 99.1 and 99.2 and are furnished, not filed, under the Exchange Act.
MPWR’s common stock trades on the NASDAQ Global Select Market under the symbol MPWR. The company notes it operates across the US, Europe, and Asia and does not maintain a single headquarters; addresses are included to satisfy SEC requirements.
Monolithic Power Systems (MPWR) disclosed an insider equity award. On October 25, 2025, EVP & General Counsel acquired 135,520 common shares at $0 upon certification of performance criteria for previously granted market-based RSUs (MSUs). The MSUs were granted on October 25, 2022 and tied to five stock price targets and relative TSR over a three-year period. All awarded shares fully vested on October 25, 2025.
Following the transaction, the reporting person beneficially owned 261,874 shares, held directly.
Monolithic Power Systems (MPWR) filed a Form 4 showing its EVP and CFO received 87,690 shares of common stock on October 25, 2025. The shares were awarded at $0 upon certification and approval of performance goals tied to market-based RSUs granted on October 25, 2022; all shares fully vested on October 25, 2025.
Following the award, the reporting person beneficially owns 125,630 shares directly. In addition, 5,331 shares are held indirectly in an Irrevocable Trust FBO Theodore F. Blegen and 5,331 shares are held indirectly in an Irrevocable Trust FBO Sarah N. Blegen.
Monolithic Power Systems (MPWR) disclosed an insider equity vesting: CEO and Director Michael R. Hsing was awarded 302,920 shares of common stock on October 25, 2025 at $0 per share after the Compensation Committee certified performance for previously granted market-based RSUs.
The MSUs, granted on October 25, 2022, were tied to five stock price targets and relative total stockholder return over a three-year period; all awarded shares fully vested on October 25, 2025.
Following the transaction, Hsing beneficially owned 1,117,587 shares directly, plus 133,040 held indirectly by the M Hsing 04 Trust and 12,825 held indirectly by the ZH Family 2020 Trust.