Haiping Dun sold $331k of ACMR
director at ACM Research, Inc.. 5,000 shares at an average of $66.22, traded May 19, 2026, filed May 21, 2026.
Score components
- +15RoleDirector
- +15Trade size$331k at market
- +20Share of holdings soldSold 100% of holdings
- 0ClusterNo other insider selling within 14 days
- -15Exercise and sellShares came from an option exercise in the same filing
- -2010b5-1 planPre-scheduled under a 10b5-1 plan
What happened after comparable sells
Same side and tier, against the S&P 500, at 1, 3 and 6 months. Shown to Pro users; the whole table is on the backtest page.
Price around the trade, and since
From a quarter before the trade to today. The arrow is the trade, the circle the day the filing reached EDGAR, which is the first day anyone outside could act; the dotted line is the S&P 500 rebased to that day's close.
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value; the dashed line is the close on the filing day, the dotted line SPY rebased to it.Charts by TradingView Lightweight Charts™
Rows in this filing
Every transaction in Form 4 0001140361-26-022458, as filed. Open on EDGAR
| Date | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|
| May 19, 2026 | MOption exercise Class A Common Stock10b5-1 | +5,000 | $5.60 | $28k | 5,000 | May 21, 2026 |
| May 19, 2026 | SOpen-market sale Class A Common Stock10b5-1 | -1,333 | $63.84 | $85k | 3,667 | May 21, 2026 |
| May 19, 2026 | SOpen-market sale Class A Common Stock10b5-1 | -500 | $65.09 | $33k | 3,167 | May 21, 2026 |
| May 19, 2026 | SOpen-market sale Class A Common Stock10b5-1 | -1,309 | $67.21 | $88k | 1,858 | May 21, 2026 |
| May 19, 2026 | SOpen-market sale Class A Common Stock10b5-1 | -1,858 | $67.54 | $125k | 0 | May 21, 2026 |
| May 19, 2026 | MOption exercise Stock Optionderivative10b5-1 | -5,000 | $0.00 | $0 | 50,000 | May 21, 2026 |
Related signals
Other insiders at ACM Research, Inc. and this insider’s other filings.
| Score | Company | Insider | Value | Holdings | Filed |
|---|---|---|---|---|---|
| 10Weak | ACM Research, Inc. | David H Wang See Remarks | $11M 140,000 shares | -16% | |
| 33Weak | ACM Research, Inc. | Mark McKechnie See Remarks | $4.3M 55,199 shares | -98% | |
| 24Weak | ACM Research, Inc. | Haiping Dun director | $406k 5,000 shares | -100% | |
| 18Weak | ACM Research, Inc. | David H Wang See Remarks | $8.8M 100,002 shares | -12% | |
| 18Weak | ACM Research, Inc. | Sotheara Cheav See remarks | $1.6M 18,750 shares | -17% | |
| 13Weak | ACM Research, Inc. | Charles C Pappis director | $260k 5,000 shares | -100% | |
| 25Weak | ACM Research, Inc. | David H Wang See Remarks | $5.2M 110,000 shares | -13% | |
| 40Moderate | ACM Research, Inc. | Mark McKechnie See Remarks | $4.5M 98,551 shares | -162% | |
| 30Weak | ACM Research, Inc. | Tracy Liu director | $2.9M 60,000 shares | -39% | |
| 27Weak | ACM Research, Inc. | Haiping Dun director | $217k 5,000 shares | -100% |
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.