Deming Xiao is President at MONOLITHIC POWER SYSTEMS INC (MPWR). They have made 266 open-market trades across 1 company since 2006, most recently 2026-05-06.
CIK 0001308647
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 266 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| MPWR | 205,959 | $249.3M |
Shares reported on the most recent Form 4, priced at the 2026-05-08 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| MPWR | SELL | 2026-05-06 | 2026-05-08 | $1654.55 | $49.6M | -2.8% | -2.5% | -15.0% |
| MPWR | SELL | 2026-02-06 | 2026-02-10 | $1171.16 | $26.8M | +2.2% | -11.3% | +42.6% |
| MPWR | SELL · 10b5-1 | 2025-08-01 | 2025-08-04 | $780.00 | $31.2M | +2.3% | -0.3% | +21.0% |
| MPWR | SELL | 2025-02-10 | 2025-02-12 | $717.10 | $949K | -6.9% | -13.4% | +5.5% |
| MPWR | SELL | 2024-11-08 | 2024-11-13 | $765.14 | $1.3M | -0.4% | +0.9% | +15.9% |
| MPWR | SELL | 2024-08-27 | 2024-08-29 | $950.00 | $8.8M | -5.6% | -2.5% | -40.9% |
| MPWR | SELL | 2024-08-22 | 2024-08-22 | $950.00 | $9.5M | -8.2% | -3.6% | -39.5% |
| MPWR | SELL | 2024-08-08 | 2024-08-12 | $778.39 | $1.3M | +8.1% | +6.6% | -22.9% |
| MPWR | SELL | 2024-07-22 | 2024-07-24 | $831.58 | $5.3M | -2.2% | +18.8% | +11.3% |
| MPWR | SELL | 2024-05-22 | 2024-05-22 | $769.40 | $1.0M | -6.4% | +6.5% | +16.6% |
| MPWR | SELL | 2024-05-08 | 2024-05-09 | $690.02 | $1.2M | +5.2% | +8.4% | +5.2% |
| MPWR | SELL | 2024-02-08 | 2024-02-09 | $680.00 | $584K | -1.5% | -4.4% | -5.9% |
| MPWR | SELL | 2024-02-05 | 2024-02-07 | $641.00 | $629K | +4.8% | +7.7% | +3.3% |
| MPWR | SELL | 2024-01-10 | 2024-01-11 | $589.52 | $12.7M | +7.3% | +23.9% | +13.2% |
| MPWR | SELL | 2024-01-04 | 2024-01-08 | $583.14 | $29.5M | +9.1% | +11.5% | +17.8% |
| MPWR | SELL | 2023-11-08 | 2023-11-09 | $490.39 | $842K | +9.5% | +20.5% | +31.3% |
| MPWR | SELL | 2023-11-06 | 2023-11-07 | $492.92 | $968K | +10.1% | +15.9% | +31.8% |
| MPWR | SELL | 2023-10-02 | 2023-10-04 | $458.30 | $3.9M | +6.2% | +8.4% | +32.8% |
| MPWR | SELL | 2023-08-08 | 2023-08-10 | $530.26 | $927K | -1.5% | -4.4% | -3.1% |
| MPWR | SELL | 2023-08-04 | 2023-08-07 | $526.53 | $1.0M | -8.5% | -1.3% | -6.9% |
| MPWR | SELL | 2023-07-21 | 2023-07-25 | $534.23 | $10.3M | -1.0% | -10.1% | -23.8% |
| MPWR | SELL | 2023-07-03 | 2023-07-05 | $537.79 | $4.6M | +15.6% | +5.4% | -11.9% |
| MPWR | SELL | 2023-05-09 | 2023-05-10 | $409.79 | $702K | +8.2% | +21.1% | +27.8% |
| MPWR | SELL | 2023-05-04 | 2023-05-05 | $459.60 | $911K | +2.4% | +20.0% | +31.2% |
| MPWR | SELL | 2023-05-03 | 2023-05-04 | $463.55 | $3.2M | -0.6% | +20.3% | +31.0% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.