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 related filing reports proposed and recent dispositions of Common Stock by an affiliated selling holder. The filing lists four blocks of Performance Shares eligible for sale (2,980; 811; 2,377; 1,397 shares) and multiple sales by Saria Tseng in the past three months (examples: 25,674 shares on 03/30/2026, 8,964 shares on 04/08/2026). The filing is a regulatory notice of resale activity.
Monolithic Power Systems director Jeff Zhou sold 486 shares of Common Stock in an open-market sale at $1,680 per share. This transaction reduced his direct holdings to 3,800 shares after the sale, indicating a partial, not complete, trim of his position.
Monolithic Power Systems EVP & General Counsel Saria Tseng reported multiple share dispositions. On May 22, 2026, she completed an open-market sale of 5,000 shares of common stock at $1,586.43 per share, leaving 151,783 shares held directly afterward.
The filing also reports a bona fide gift transfer of 200 shares from her direct holdings to an individual who is not an immediate family member sharing the same household. The footnote states no funds were exchanged, no sale occurred, and she no longer retains any pecuniary interest in those shares.
In addition, the filing shows 1,000 shares of common stock held indirectly through the C&T Discovery Foundation.
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.