The most recent Monolithic Power Systems (MPWR) insider transaction: Maurice Sciammas (Evp, Ww Sales Marketing) gave 13,000 shares as a gift on Nov 3, 2026, reported on Form 4 on Nov 5, 2026. So far in the quarter ending Dec 31, 2026, insiders were net buyers of 8 shares.
Across the past 12 months, open-market trades by Monolithic Power Systems insiders were all sales, totaling $596.82 million (488.3K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Michael Hsing | Ceo | 1,815,010 | 0 | 1,815,010 | 48.0% | 30 Sep, 2026 |
| 2 | Maurice Sciammas | Evp, Ww Sales Marketing | 588,090 | 49,062 | 637,152 | 16.9% | 05 Nov, 2026 |
| 3 | Deming Xiao | Evp, Global Operations | 501,006 | 0 | 501,006 | 13.3% | 08 May, 2026 |
| 4 | Saria Tseng | Evp General Counsel | 403,601 | 2,000 | 405,601 | 10.7% | 02 Sep, 2026 |
| 5 | Theodore Blegen | Evp And Cfo | 361,884 | 0 | 361,884 | 9.6% | 10 Feb, 2026 |
| 6 | Victor K Lee | Director | 27,756 | 0 | 27,756 | 0.7% | 11 Feb, 2026 |
| 7 | Jeff Zhou | Director | 9,451 | 0 | 9,451 | 0.2% | 27 May, 2026 |
| 8 | James C Moyer | Director | 0 | 8,000 | 8,000 | 0.2% | 14 Feb, 2024 |
| 9 | Robert W Ii Dean | Interim Cfo | 7,089 | 0 | 7,089 | 0.2% | 26 Aug, 2026 |
| 10 | Eugen J Elmiger | Director | 5,402 | 0 | 5,402 | 0.1% | 08 May, 2026 |
| 11 | Carintia Martinez | Director | 1,067 | 0 | 1,067 | 0.0% | 03 Feb, 2026 |
| 12 | Eileen Wynne | Director | 1,007 | 0 | 1,007 | 0.0% | 08 May, 2026 |
| 13 | Kuo Wei Herbert Chang | Director | 515 | 0 | 515 | 0.0% | 25 Aug, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 03 Nov, 2026 | Maurice Sciammas | Evp, Ww Sales Marketing | Disposed G | 13,000 | $0.00 | $0 | 113,652 | Direct |
| 03 Nov, 2026 | Maurice Sciammas | Evp, Ww Sales Marketing | Acquired G | 13,000 | $0.00 | $0 | 49,062 | Indirect |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 596 | $1,323.31 | $788.69K | 847,668 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 2,121 | $1,328.54 | $2.82Mn | 845,547 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 1,111 | $1,333.34 | $1.48Mn | 844,436 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 2,949 | $1,338.66 | $3.95Mn | 841,487 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 5,783 | $1,343.76 | $7.77Mn | 835,704 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 6,343 | $1,347.15 | $8.54Mn | 829,361 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 10,967 | $1,351.43 | $14.82Mn | 818,394 | Direct |
| 28 Sep, 2026 | Michael Hsing | Ceo | Disposed S | 130 | $1,356.94 | $176.40K | 818,264 | Direct |
| 31 Aug, 2026 | Saria Tseng | Evp General Counsel | Disposed G | 2,000 | $0.00 | $0 | 142,218 | Direct |
| 31 Aug, 2026 | Saria Tseng | Evp General Counsel | Acquired G | 2,000 | $0.00 | $0 | 2,000 | Indirect |
| 24 Aug, 2026 | Robert W Ii Dean | Interim Cfo | Disposed S | 32 | $1,297.72 | $41.53K | 7,094 | Direct |
| 24 Aug, 2026 | Robert W Ii Dean | Interim Cfo | Disposed J | 5 | $0.00 | $0 | 7,089 | Direct |
| 24 Aug, 2026 | Kuo Wei Herbert Chang | Director | Disposed S | 50 | $1,281.57 | $64.08K | 515 | Direct |
| 17 Aug, 2026 | Robert W Ii Dean | Interim Cfo | Disposed S | 6 | $1,413.64 | $8.48K | 7,126 | Direct |
| 11 Aug, 2026 | Kuo Wei Herbert Chang | Director | Disposed S | 50 | $1,420.00 | $71.00K | 565 | Direct |
| 05 Aug, 2026 | Robert W Ii Dean | Interim Cfo | Disposed S | 105 | $1,344.27 | $141.15K | 7,132 | Direct |
| 04 Aug, 2026 | Maurice Sciammas | Evp, Ww Sales Marketing | Disposed G | 25,000 | $0.00 | $0 | 126,644 | Direct |
| 04 Aug, 2026 | Maurice Sciammas | Evp, Ww Sales Marketing | Acquired G | 25,000 | $0.00 | $0 | 36,062 | Indirect |