Every Form 4 that Monolithic Power Systems, Inc. (MPWR) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow MPWR and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full MPWR filings page.
Monolithic Power Systems director Carintia Martinez reported an annual equity award in the form of restricted stock units. On February 3, 2026, she acquired 189 shares of common stock at $0 per share, bringing her directly held beneficial ownership to 1,067 shares.
The grant was part of the company’s regular annual restricted stock unit program for independent directors. According to the disclosure, this RSU award will vest one year after the grant date, provided she continues serving on the board during that period.
Monolithic Power Systems executive Deming Xiao reported a stock award tied to prior performance-based incentives. As EVP, Global Operations, he received 57,170 shares of common stock on February 3, 2026 at $0 per share, following the certification of performance-based restricted stock units granted in 2023. After this vesting, he beneficially owns 258,807 shares directly, plus 20,455 shares held indirectly by his spouse and 4,336 shares held indirectly through the Christopher Chao Xiao Trust.
Monolithic Power Systems EVP and CFO Theodore Blegen received 38,745 shares of common stock on February 3, 2026 through the vesting of previously granted performance-based restricted stock units. These shares were awarded at a price of $0 per share following certification of performance goals for a three-year period that began with a February 7, 2023 grant.
After this award, Blegen directly beneficially owned 104,078 shares of Monolithic Power Systems common stock. He also indirectly beneficially owned 5,331 shares held in an irrevocable trust for Sarah N. Blegen and another 5,331 shares held in an irrevocable trust for Theodore F. Blegen.
Monolithic Power Systems EVP & General Counsel Saria Tseng received 57,170 common shares on February 3, 2026 from previously granted performance-based restricted stock units. The company’s Compensation Committee certified that three-year performance goals were achieved, causing all units to fully vest and be released the same day at a price of $0 per share.
After this award, Tseng directly beneficially owned 223,501 shares of Monolithic Power Systems common stock and indirectly held 1,000 additional shares through C&T Discovery Foundation.
Monolithic Power Systems CEO Michael Hsing, who is also a director, reported the vesting of 136,825 shares of common stock on February 3, 2026. These shares came from performance-based restricted stock units granted on February 7, 2023 after a three-year performance period and were awarded at a price of $0 per share, subject to tax withholding.
After this award, Hsing directly beneficially owned 1,043,157 shares of common stock. In addition, indirect holdings totaled 133,040 shares through the M Hsing 04 Trust and 12,825 shares through the ZH Family 2020 Trust.
Monolithic Power Systems executive Maurice Sciammas reported a stock award tied to prior performance-based units. As EVP, WW Sales & Marketing, he received 57,170 shares of common stock on February 3, 2026, at a price of $0 after the company’s Compensation Committee certified performance goals for PSUs granted on February 7, 2023.
All 57,170 shares fully vested and were released the same day, bringing his directly held common stock to 201,500 shares. Additional indirect holdings are reported in various family trusts and accounts.
Monolithic Power Systems executive vice president and CFO Theodore Blegen reported multiple open‑market sales of common stock on February 2, 2026 under a pre‑arranged Rule 10b5‑1 trading plan. The trades involved small blocks of shares at weighted average prices ranging roughly from $1,110.14 to $1,139.54 per share. After these transactions, Blegen directly beneficially owned 65,333 common shares and indirectly held 5,331 shares in each of two irrevocable trusts for Sarah N. Blegen and Theodore F. Blegen.
Monolithic Power Systems executive Theodore Blegen, EVP and CFO, reported planned stock sales under a Rule 10b5-1 trading plan. On January 2, 2026, he sold multiple small blocks of Monolithic Power Systems common stock at prices between $927.61 and $946.62 per share, as disclosed across several transaction lines. These trades were executed pursuant to a Rule 10b5-1 plan adopted on February 26, 2025, which allows pre-arranged sales according to preset instructions.
Following these transactions, Blegen directly held 68,332 shares of common stock. The filing also shows indirect beneficial ownership of 5,331 shares held in an irrevocable trust for Sarah N. Blegen and another 5,331 shares held in an irrevocable trust for Theodore F. Blegen, reflecting additional trust-related holdings associated with the reporting person.
Monolithic Power Systems CEO and director Michael R. Hsing transferred 12,337 shares of common stock as a gift to a 501(c)(3) foundation on 12/09/2025. The company states that after the transfer he has no management or investment control and no pecuniary interest in those shares, and no funds were exchanged, so no sale occurred.
Following the transaction, Hsing beneficially owned 906,332 shares directly, plus 133,040 shares held indirectly through the M Hsing 04 Trust and 12,825 shares held indirectly through the ZH Family 2020 Trust.
Monolithic Power Systems Inc. (MPWR) director transaction reported. A company director reported the sale of 100 shares of Monolithic Power Systems common stock in an open market transaction. The sale took place at a price of $896.97 per share. After this transaction, the director reports beneficial ownership of 426 shares held directly.
Monolithic Power Systems (MPWR) executive Maurice Sciammas, EVP of Worldwide Sales & Marketing, reported a stock sale in a Form 4 filing. On 11/24/2025, he sold 3,976 shares of MPWR common stock at a price of $895.23 per share, coded as a sale transaction. After this trade, he directly owns 144,330 shares of common stock and also reports additional indirect holdings through multiple family trusts and related accounts, reflecting ongoing significant ownership in the company.
Monolithic Power Systems (MPWR) director reports small stock sale. A company director filed a Form 4 showing the sale of 100 shares of MPWR common stock on 11/21/2025 at a price of $873.97 per share, coded as a sale transaction ("S").
Following this trade, the director beneficially owns 526 shares of MPWR common stock in direct ownership. The filing is made by a single reporting person in the capacity of director and does not report any derivative securities activity.
Monolithic Power Systems (MPWR) reported insider activity by its EVP, WW Sales & Marketing, in a Form 4 filing. On 11/19/2025, the executive sold multiple blocks of common stock in open market transactions coded "S" for sales.
The reported trades covered relatively small share blocks at weighted average prices ranging from about $875.26 to $886.01, with detailed price ranges provided for each group of sales. After these transactions, the reporting person directly held 148,306 shares of MPWR common stock.
The filing also lists additional indirect beneficial ownership in various family trusts and related accounts, each holding smaller amounts of MPWR shares. The trades were reported as having been made under a Rule 10b5-1 trading arrangement, which is a pre-established plan for buying or selling stock.
Monolithic Power Systems (MPWR) executive vice president of worldwide sales and marketing Maurice Sciammas reported multiple open-market sales of common stock on 11/19/2025. Across a series of trades, he sold a total of 7,034 shares at weighted average prices reported between about $862 and $875 per share, with detailed price ranges noted for each trade.
After these transactions, Sciammas directly owned 176,272 shares of MPWR common stock and also had additional indirect holdings through various family trusts and accounts, including positions such as 49,460 shares in the Sciammas Family Trust and other named family and irrevocable trusts. The footnotes state that the reported prices are weighted averages and that full trade-by-trade price information is available upon request.
Monolithic Power Systems (MPWR) reported insider transactions by CEO and director Michael R. Hsing. On 11/12/2025, he executed multiple open‑market sales of common stock at disclosed weighted‑average prices, with per‑line price ranges provided.
Following the transactions, Hsing beneficially owns 918,669 shares directly. He also holds indirect positions of 133,040 shares via the M Hsing 04 Trust and 12,825 shares via the ZH Family 2020 Trust.
Monolithic Power Systems (MPWR) CEO and director Michael R. Hsing reported open-market sales of 40,000 shares of common stock on 11/11/2025 across multiple transactions. The filing lists weighted-average prices for each tranche, with disclosed price ranges from $952.05 to $967.17 for the respective trades. Following these sales, Hsing directly holds 955,669 shares.
The filing also shows indirect holdings of 133,040 shares by the M Hsing 04 Trust and 12,825 shares by the ZH Family 2020 Trust.
Monolithic Power Systems (MPWR) reported an insider transaction by its EVP, WW Sales & Marketing. On 11/05/2025, the reporting person sold 200 shares of common stock at $986.81 per share.
Following the transaction, the report lists beneficial ownership positions, including 183,306 shares direct and 44,930 shares held indirectly in the Sciammas Family Trust, among various other family trusts and accounts.
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.