Monolithic Power Systems (MPWR) — insider trading
Information Technology · NASDAQ
Monolithic Power Systems (MPWR) has 90 reported SEC Form 4 insider transactions in our data, including 79 open-market sales among the most recent 90 (latest 2026-09-28).
Recent Form 4 transactions
| Date | Insider | Role | Type | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 130 | $1,356.94 | $176.4K | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 10,967 | $1,351.43 | $14.82M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 6,343 | $1,347.15 | $8.54M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 5,783 | $1,343.76 | $7.77M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 2,949 | $1,338.66 | $3.95M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 1,111 | $1,333.34 | $1.48M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 2,121 | $1,328.54 | $2.82M | Form 4 |
| 2026-09-28 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 596 | $1,323.31 | $788.7K | Form 4 |
| 2026-08-31 | Tseng Saria | Officer (EVP & General Counsel) | Bona fide gift | 2,000 | — | $0 | Form 4 |
| 2026-08-31 | Tseng Saria | Officer (EVP & General Counsel) | Bona fide gift | 2,000 | — | $0 | Form 4 |
| 2026-08-24 | DEAN ROBERT W II | Officer (Interim CFO) | Other acquisition or disposition | 5 | — | $0 | Form 4 |
| 2026-08-24 | DEAN ROBERT W II | Officer (Interim CFO) | Open-market sale | 32 | $1,297.72 | $41.5K | Form 4 |
| 2026-08-24 | CHANG KUO WEI HERBERT | Director | Open-market sale | 50 | $1,281.57 | $64.1K | Form 4 |
| 2026-08-17 | DEAN ROBERT W II | Officer (Interim CFO) | Open-market sale | 6 | $1,413.64 | $8.5K | Form 4 |
| 2026-08-11 | CHANG KUO WEI HERBERT | Director | Open-market sale | 50 | $1,420.00 | $71.0K | Form 4 |
| 2026-08-05 | DEAN ROBERT W II | Officer (Interim CFO) | Open-market sale | 105 | $1,344.27 | $141.1K | Form 4 |
| 2026-08-04 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Bona fide gift | 25,000 | — | $0 | Form 4 |
| 2026-08-04 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Bona fide gift | 25,000 | — | $0 | Form 4 |
| 2026-08-03 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 30 | $1,343.94 | $40.3K | Form 4 |
| 2026-07-25 | DEAN ROBERT W II | Officer (Interim CFO) | Grant / award / vesting | 1,359 | — | $0 | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 110 | $1,405.71 | $154.6K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 117 | $1,400.45 | $163.9K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 213 | $1,396.16 | $297.4K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 50 | $1,388.19 | $69.4K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 410 | $1,384.11 | $567.5K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 418 | $1,378.73 | $576.3K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 472 | $1,375.47 | $649.2K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 240 | $1,369.18 | $328.6K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 50 | $1,359.36 | $68.0K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 5,640 | $1,352.95 | $7.63M | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 1,506 | $1,348.91 | $2.03M | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 1,864 | $1,344.16 | $2.51M | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 1,460 | $1,339.59 | $1.96M | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 776 | $1,334.59 | $1.04M | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 464 | $1,329.30 | $616.8K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 409 | $1,323.93 | $541.5K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 274 | $1,318.42 | $361.2K | Form 4 |
| 2026-07-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 527 | $1,314.03 | $692.5K | Form 4 |
| 2026-07-01 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 30 | $1,351.61 | $40.5K | Form 4 |
| 2026-06-01 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 30 | $1,533.95 | $46.0K | Form 4 |
| 2026-05-29 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Bona fide gift | 12,472 | — | $0 | Form 4 |
| 2026-05-27 | Tseng Saria | Officer (EVP & General Counsel) | Open-market sale | 7,565 | $1,700.00 | $12.86M | Form 4 |
| 2026-05-26 | DEAN ROBERT W II | Officer (Interim CFO) | Open-market sale | 22 | $1,649.56 | $36.3K | Form 4 |
| 2026-05-26 | Zhou Jeff | Director | Open-market sale | 486 | $1,680.00 | $816.5K | Form 4 |
| 2026-05-22 | Tseng Saria | Officer (EVP & General Counsel) | Open-market sale | 5,000 | $1,586.43 | $7.93M | Form 4 |
| 2026-05-22 | Tseng Saria | Officer (EVP & General Counsel) | Bona fide gift | 200 | — | $0 | Form 4 |
| 2026-05-18 | DEAN ROBERT W II | Officer (Interim CFO) | Open-market sale | 4 | $1,563.28 | $6.3K | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 130 | $1,521.43 | $197.8K | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 352 | $1,518.15 | $534.4K | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 551 | $1,513.11 | $833.7K | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 3,769 | $1,507.70 | $5.68M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 2,929 | $1,503.05 | $4.40M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 608 | $1,499.46 | $911.7K | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 862 | $1,491.48 | $1.29M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 6,688 | $1,486.76 | $9.94M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 5,737 | $1,482.51 | $8.51M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 4,082 | $1,476.96 | $6.03M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 5,049 | $1,472.84 | $7.44M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 5,819 | $1,467.62 | $8.54M | Form 4 |
| 2026-05-18 | Hsing Michael | Director, Officer (CEO) | Open-market sale | 3,424 | $1,462.61 | $5.01M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 50 | $1,585.51 | $79.3K | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 447 | $1,582.21 | $707.2K | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 703 | $1,577.75 | $1.11M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 1,312 | $1,571.49 | $2.06M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 2,020 | $1,567.15 | $3.17M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 2,010 | $1,562.01 | $3.14M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 1,717 | $1,557.48 | $2.67M | Form 4 |
| 2026-05-15 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 3,741 | $1,550.36 | $5.80M | Form 4 |
| 2026-05-13 | DEAN ROBERT W II | Officer (Interim CFO) | Other acquisition or disposition | 2,156 | — | $0 | Form 4 |
| 2026-05-13 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Bona fide gift | 1,563 | — | $0 | Form 4 |
| 2026-05-13 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Bona fide gift | 1,563 | — | $0 | Form 4 |
| 2026-05-06 | Wynne Eileen | Director | Open-market sale | 335 | $1,582.68 | $530.2K | Form 4 |
| 2026-05-06 | Xiao Deming | Officer (EVP, Global Operations) | Open-market sale | 907 | $1,661.38 | $1.51M | Form 4 |
| 2026-05-06 | Xiao Deming | Officer (EVP, Global Operations) | Open-market sale | 11,597 | $1,657.93 | $19.23M | Form 4 |
| 2026-05-06 | Xiao Deming | Officer (EVP, Global Operations) | Open-market sale | 14,167 | $1,652.80 | $23.42M | Form 4 |
| 2026-05-06 | Xiao Deming | Officer (EVP, Global Operations) | Open-market sale | 3,329 | $1,648.38 | $5.49M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 514 | $1,600.14 | $822.5K | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 2,619 | $1,596.42 | $4.18M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 1,355 | $1,591.38 | $2.16M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 2,587 | $1,586.81 | $4.11M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 1,879 | $1,581.81 | $2.97M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 834 | $1,575.57 | $1.31M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 1,078 | $1,571.58 | $1.69M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 814 | $1,566.36 | $1.28M | Form 4 |
| 2026-05-06 | Elmiger Eugen J | Director | Open-market sale | 320 | $1,559.88 | $499.2K | Form 4 |
| 2026-05-06 | Zhou Jeff | Director | Open-market sale | 500 | $1,650.00 | $825.0K | Form 4 |
| 2026-05-05 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 380 | $1,583.81 | $601.8K | Form 4 |
| 2026-05-05 | Zhou Jeff | Director | Open-market sale | 500 | $1,600.00 | $800.0K | Form 4 |
| 2026-05-05 | Zhou Jeff | Director | Open-market sale | 514 | $1,574.48 | $809.3K | Form 4 |
| 2026-05-04 | Sciammas Maurice | Officer (EVP, WW Sales & Marketing) | Open-market sale | 30 | $1,588.73 | $47.7K | Form 4 |
Ask the chat about MPWR's insider activity →
Transaction types are the SEC Form 4 codes: open-market purchases (P) and sales (S) are the only rows that reflect open-market conviction. Awards/vesting (A), option exercises (M/X/C), shares withheld for taxes (F) and gifts (G) are compensation or mechanical, not buying or selling on the open market. Sales may be planned and non-discretionary (e.g. a Rule 10b5-1 plan); open-market buying is not a recommendation to buy. Informational only — not financial advice.
Source: SEC EDGAR Form 3/4/5. See the full company profile: Monolithic Power Systems (MPWR).
Last updated 2026-09-28 (most recent filing date).
Informational only — NOT financial advice. Insider filings are sourced from SEC EDGAR and shown with their reported dates.