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.
Vanguard Capital Management reported beneficial ownership of 3,561,866 shares of Monolithic Power Systems Inc. The filing, covering holdings as of 03/31/2026, shows a 7.25% stake in the common stock. Vanguard reports sole dispositive power over 3,561,866 shares and sole voting power for 478,417 shares. The statement discloses that the position reflects holdings across Vanguard Capital Management LLC and affiliated business divisions and funds. The filing is signed by the Head of Global Fund Administration on 04/30/2026.
Vanguard Capital Management reported beneficial ownership of 3,561,866 shares of Monolithic Power Systems Inc. The filing, covering holdings as of 03/31/2026, shows a 7.25% stake in the common stock. Vanguard reports sole dispositive power over 3,561,866 shares and sole voting power for 478,417 shares. The statement discloses that the position reflects holdings across Vanguard Capital Management LLC and affiliated business divisions and funds. The filing is signed by the Head of Global Fund Administration on 04/30/2026.
Monolithic Power Systems Inc ownership reported by Vanguard Portfolio Management: 2,528,928 shares, representing 5.14% of common stock. The filing states Vanguard Portfolio Management LLC has sole dispositive power over 2,528,928 shares and sole voting power over 12,436 shares, signed 04/29/2026.
Monolithic Power Systems EVP & General Counsel Saria Tseng reported open-market sales of 8,963 shares of common stock on April 8, 2026 under a pre-arranged Rule 10b5-1 trading plan adopted on November 28, 2025. Sale prices included tranches at about $1,266.48 and $1,312.82 per share. After these transactions, she directly holds 156,983 shares and indirectly holds 1,000 shares through the C&T Discovery Foundation.
SARIA TSENG filed Form 144 notices reporting dispositions of Common shares. The filing lists four sales: 25,674 shares on 03/30/2026 for $25,943,648.15, 22,876 shares on 02/06/2026 for $26,791,540.80, 7,636 shares on 04/06/2026 for $8,918,428.78, and 1,400 shares on 04/01/2026 for $1,586,924.78.
The filing also lists issuer grants of performance shares dated 07/20/2024 (4,835), 08/07/2024 (1,313), 11/07/2024 (1,306), and 02/07/2025 (1,510).
MONOLITHIC POWER SYSTEMS INC executive Saria Tseng sold 7,636 shares of Common Stock in open-market transactions. The EVP & General Counsel executed eight planned sales on April 6, 2026 under a Rule 10b5-1 trading plan adopted on November 28, 2025, at prices such as $1,139.96, $1,170.38 and $1,179.50 per share. After these trades, Tseng holds 169,022 shares directly and 1,000 shares indirectly through C&T Discovery Foundation.
MPWR filing a Form 144 notice for proposed sales of Common stock by an individual Saria Tseng. The excerpt lists three proposed sale dates with share counts: 1,400 on 04/01/2026, 25,674 on 03/30/2026, and 22,876 on 02/06/2026. The filing names Morgan Stanley Smith Barney LLC as the broker.
Monolithic Power Systems EVP & General Counsel Saria Tseng reported open-market sales of 1,400 shares of common stock on April 1, 2026. The trades occurred in multiple blocks at weighted average prices ranging from about $1,130.82 to $1,137.71 per share under a pre-arranged Rule 10b5-1 trading plan adopted on November 28, 2025. After these transactions, she directly holds 173,582 shares and has an additional 1,000 shares reported as indirectly held through C&T Discovery Foundation.
Monolithic Power Systems EVP Maurice Sciammas, through the Clement Sciammas Trust, sold 30 shares of common stock in an open-market transaction at $1,116.44 per share on April 1, 2026.
The trust held 1,239 shares after the sale as indirect ownership. Sciammas also held 178,644 shares directly, while other related trusts and accounts held additional indirect positions, including 49,460 shares in the Sciammas Family Trust and 26,660 shares in various Sciammas GRATs. The sale was made under a Rule 10b5-1 trading plan adopted on November 19, 2025.
Monolithic Power Systems EVP & General Counsel Saria Tseng reported selling a total of 25,674 shares of common stock in multiple open-market transactions on March 30, 2026. The weighted-average sale prices for these trades ranged from about $998 to $1,042 per share, as detailed in price-range footnotes.
The filing notes these transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on November 28, 2025. After the sales, Tseng directly holds 174,982 shares and has an additional 1,000 shares held indirectly through the C&T Discovery Foundation.
Morgan Stanley Smith Barney LLC submitted a Form 144 notice relating to Common stock described as Performance Shares. The filing lists 1400 in the securities row and records recent sales by Saria Tseng: 22,876 shares on 02/06/2026 and 25,674 shares on 03/30/2026.