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Monolithic Power Systems, Inc. (MPWR)
NASDAQ: MPWR · Real-Time Price · USD
Technology · Semiconductors
1171.34+31.22 (+2.74%)
Insider Score
––Not scored
MPWR Insider Score
Insiders filed in the last 90 days, but none of those trades qualified for scoring — round-trip buys and filings whose price is far off the market are excluded.
MPWR Stock Insider Trading Activity
MPWR stock’s insider trading shows 22 sales on the open market for an estimated $50.46M by company insiders over the last 6 months.
Not enough price history.
Insider Trading Activity (Form 4 Filings)
An insider trade occurs when an individual that has non-public information about a company buys or sells shares of that company’s stock. Examples of insiders include a company’s executive officers (CEO, CFO, COO), its board of directors, and its major shareholders. Insiders are required to submit their trading activity to the SEC through Form 4 filings.
Scored window · last 90 days0 qualifying buys0 insiders$0 bought— these are the numbers in the rankings table; the full history below shows every filing (buys, sells and older activity).
| Insider | Action | Shares | Avg Cost | Total | Δ Holdings | Held After | Date | Grade | Form 4 |
|---|---|---|---|---|---|---|---|---|---|
| Hsing Michael CEO | Sell | 596 | $1323.31 | $788.69K | 0.1% | 847,668 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 2,121 | $1328.54 | $2.82M | 0.3% | 845,547 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 1,111 | $1333.34 | $1.48M | 0.1% | 844,436 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 2,949 | $1338.66 | $3.95M | 0.3% | 841,487 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 5,783 | $1343.76 | $7.77M | 0.7% | 835,704 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 6,343 | $1347.15 | $8.54M | 0.8% | 829,361 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 10,967 | $1351.43 | $14.82M | 1.3% | 818,394 | Sep 28, 2026 | — | Form 4 |
| Hsing Michael CEO | Sell | 130 | $1356.94 | $176.40K | 0.0% | 818,264 | Sep 28, 2026 | — | Form 4 |
| Tseng Saria Other | Gift | 2,000 | — | — | 1.4% | 142,218 | Aug 31, 2026 | — | Form 4 |
| Tseng Saria Other | Gift | 2,000 | — | — | New | 2,000 | Aug 31, 2026 | — | Form 4 |
| CHANG KUO WEI HERBERT Director | Sell | 50 | $1281.57 | $64.08K | 8.8% | 515 | Aug 24, 2026 | — | Form 4 |
| DEAN ROBERT W II CFO | Sell | 32 | $1297.72 | $41.53K | 0.4% | 7,094 | Aug 24, 2026 | — | Form 4 |
| DEAN ROBERT W II CFO | Other | 5 | — | — | 0.1% | 7,089 | Aug 24, 2026 | — | Form 4 |
| DEAN ROBERT W II CFO | Sell | 6 | $1413.64 | $8.48K | 0.1% | 7,126 | Aug 17, 2026 | — | Form 4 |
| CHANG KUO WEI HERBERT Director | Sell | 50 | $1420.00 | $71.00K | 8.1% | 565 | Aug 11, 2026 | — | Form 4 |
| DEAN ROBERT W II CFO | Sell | 105 | $1344.27 | $141.15K | 1.5% | 7,132 | Aug 5, 2026 | — | Form 4 |
| Sciammas Maurice Other | Gift | 25,000 | — | — | 16.5% | 126,644 | Aug 4, 2026 | — | Form 4 |
| Sciammas Maurice Other | Gift | 25,000 | — | — | 226% | 36,062 | Aug 4, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 30 | $1343.94 | $40.32K | 2.6% | 1,119 | Aug 3, 2026 | — | Form 4 |
| DEAN ROBERT W II CFO | Award | 1,359 | — | — | 23.1% | 7,237 | Jul 25, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 527 | $1314.03 | $692.49K | 0.3% | 166,117 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 274 | $1318.42 | $361.25K | 0.2% | 165,843 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 409 | $1323.93 | $541.49K | 0.2% | 165,434 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 464 | $1329.30 | $616.80K | 0.3% | 164,970 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 776 | $1334.59 | $1.04M | 0.5% | 164,194 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 1,460 | $1339.59 | $1.96M | 0.9% | 162,734 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 1,864 | $1344.16 | $2.51M | 1.1% | 160,870 | Jul 15, 2026 | — | Form 4 |
| Sciammas Maurice Other | Sell | 1,506 | $1348.91 | $2.03M | 0.9% | 159,364 | Jul 15, 2026 | — | Form 4 |
What these mean— the action is the SEC’s own Form 4 transaction code. Only a buy or a sell is an open-market trade; the rest are transfers, awards and exercises, which is why they carry no price.
- Sell (S) — Open-market or private sale
- Award (A) — Grant or award from the company, not a purchase
- Gift (G) — Bona fide gift
- Other (J) — Other acquisition or disposition — the filing explains it in a footnote
Disclaimer — Informational only — not investment advice. Insider transaction data is sourced from SEC Form 4 filings; market data from public feeds and may be delayed. The Insider Score is a proprietary score for research purposes and does not predict future performance. Always do your own research.