Form 4: Monolithic Power Systems CEO Sells Shares
Insider Transaction (Form 4)
Michael Hsing, CEO and a Director of Monolithic Power Systems Inc, sold 30,000 shares of common stock on September 28, 2026.
Summary
- Open-market sale: disposed of 596 Common Stock at $1,323.31 ($788,693) on September 28, 2026; holds 847,668 after (Direct).
- Open-market sale: disposed of 2,121 Common Stock at $1,328.54 ($2,817,833) on September 28, 2026; holds 845,547 after (Direct).
- Open-market sale: disposed of 1,111 Common Stock at $1,333.34 ($1,481,341) on September 28, 2026; holds 844,436 after (Direct).
- Open-market sale: disposed of 2,949 Common Stock at $1,338.66 ($3,947,708) on September 28, 2026; holds 841,487 after (Direct).
- Open-market sale: disposed of 5,783 Common Stock at $1,343.76 ($7,770,964) on September 28, 2026; holds 835,704 after (Direct).
- Open-market sale: disposed of 6,343 Common Stock at $1,347.15 ($8,544,972) on September 28, 2026; holds 829,361 after (Direct).
- Open-market sale: disposed of 10,967 Common Stock at $1,351.43 ($14,821,133) on September 28, 2026; holds 818,394 after (Direct).
- Open-market sale: disposed of 130 Common Stock at $1,356.94 ($176,402) on September 28, 2026; holds 818,264 after (Direct).
Sentiment
Score: 4
Explanation: StockSavvy.ai views this as a mildly negative but low-conviction signal: an insider sold $40,349,047 of stock under a pre-arranged Rule 10b5-1 plan, which is typically routine.
Insider Transactions
Michael Hsing — Director, Officer (CEO)
Transaction made under a Rule 10b5-1 trading plan.
| Date | Transaction | Security | Shares | Price | Value | Held After |
|---|---|---|---|---|---|---|
| 2026-09-28 | Open-market sale | Common Stock | 596 | $1.3K | $788.7K | 847,668 |
| 2026-09-28 | Open-market sale | Common Stock | 2,121 | $1.3K | $2.8M | 845,547 |
| 2026-09-28 | Open-market sale | Common Stock | 1,111 | $1.3K | $1.5M | 844,436 |
| 2026-09-28 | Open-market sale | Common Stock | 2,949 | $1.3K | $3.9M | 841,487 |
| 2026-09-28 | Open-market sale | Common Stock | 5,783 | $1.3K | $7.8M | 835,704 |
| 2026-09-28 | Open-market sale | Common Stock | 6,343 | $1.3K | $8.5M | 829,361 |
| 2026-09-28 | Open-market sale | Common Stock | 10,967 | $1.4K | $14.8M | 818,394 |
| 2026-09-28 | Open-market sale | Common Stock | 130 | $1.4K | $176.4K | 818,264 |
Key Dates
| Date | Description |
|---|---|
| 2026-09-28 | Open-market sale (596 shares) |
| 2026-09-28 | Open-market sale (2,121 shares) |
| 2026-09-28 | Open-market sale (1,111 shares) |
| 2026-09-28 | Open-market sale (2,949 shares) |
| 2026-09-28 | Open-market sale (5,783 shares) |
| 2026-09-28 | Open-market sale (6,343 shares) |
| 2026-09-28 | Open-market sale (10,967 shares) |
| 2026-09-28 | Open-market sale (130 shares) |
Keywords
insider transaction, Form 4, MPWR, MONOLITHIC POWER SYSTEMS, INC., bearish, Michael Hsing
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