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.
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.
MPWR submitted a Rule 144 notice listing resale of Common stock that originated as restricted stock dated 02/07/2013. The filing shows two reported dispositions by Jeff Zhou: 1,014 shares on 05/05/2026 and 500 shares on 05/06/2026, with dollar amounts displayed alongside each sale.
Insider sales reported under Form 144 by Saria Tseng. The filing lists multiple dispositions of Common Stock with specific sale dates and share counts: 25,674 shares on 03/30/2026, 1,400 shares on 04/01/2026, 7,636 shares on 04/06/2026, and 8,964 shares on 04/08/2026. Each sale row includes a cash amount received shown in the excerpt. The filing also lists holdings described as Performance Shares with grant dates of 01/01/2024 and per-row counts visible in the excerpt.
Monolithic Power Systems CEO Michael Hsing sold 40,000 shares of common stock in open-market transactions. The Form 4 shows 13 separate sales on May 18, 2026, with reported prices including $1,467.62, $1,486.76 and $1,521.43 per share.
After these sales, Hsing directly holds 879,020 shares. He also has indirect holdings of 12,825 shares through the ZH Family 2020 Trust and 133,040 shares through the M Hsing 04 Trust. A footnote notes that the ending balance includes 29 shares acquired through the company’s qualified ESPP program.
MONOLITHIC POWER SYSTEMS INC interim CFO Robert W. Dean II reported a small share sale primarily for tax purposes. On vesting of restricted stock units, 4 shares of Common Stock were sold at $1,563.28 per share to cover tax withholding obligations, leaving him with 5,900 directly held shares. A separate entry shows 65 shares held indirectly as "Held by Parent & Daughter," which reflects additional family-related ownership.
Monolithic Power Systems executive Maurice Sciammas, EVP of Worldwide Sales & Marketing, reported open-market sales of 12,000 shares of common stock on May 15, 2026. The shares were sold in multiple transactions at prices generally ranging from about $1,550 to $1,586 per share.
The filing states these sales were made under a Rule 10b5-1 trading plan adopted on November 24, 2025, indicating they were pre-arranged. Following the transactions, Sciammas directly holds 166,644 shares of Monolithic Power Systems common stock, in addition to various indirect holdings through family trusts and related accounts.
Robert Dean filed a Form 144 reporting proposed sale activity in Common Stock. The filing lists a prior sale of 85 shares on 02/23/2026 for $101,787.00. The excerpt also references time-based restricted stock units dated 05/15/2026 and contains broker/contact information for Morgan Stanley Smith Barney LLC.
MONOLITHIC POWER SYSTEMS INC executive Maurice Sciammas reported intra-family gifts of company common stock. On 2026-05-13, entities associated with him made two bona fide gift transfers totaling 3,126 shares, with 1,563 shares moved in each transaction.
The shares were transferred between three GRATs and the Sciammas Family Trust, all of which list him as a trustee. Footnotes state no funds were exchanged and no sale of shares occurred, meaning these are non-market, non-cash movements of existing holdings.
After these transfers, the Sciammas Family Trust held 51,023 shares and various Sciammas GRATs held 25,097 shares. Separately, Sciammas is shown with 178,644 shares held directly, plus additional indirect positions through several other family trusts and accounts.
MPWR filing reports proposed resale of 12,000 common shares through Morgan Stanley Smith Barney LLC with an execution date listed as 05/15/2026 on NASDAQ. The filing also lists performance shares dated 10/25/2025 totaling 12,000 and recent sales by Maurice Sciammas: 380, 30, 30, and 30 common shares on 05/05/2026, 05/04/2026, 04/01/2026, and 03/20/2026, respectively.