ACMR · Insider Trading
ACM Research, Inc. Class A Common Stock
Every open-market purchase and sale reported by ACMR officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-09-10 | David H Wang | See Remarks | MIXED | — | −$10.49M |
| 2026-08-26 | Charles C Pappis | Director | A | +7,128 deriv. | — |
| 2026-08-26 | Tracy Liu | Director | A | +7,128 deriv. | — |
| 2026-08-26 | Haiping Dun | Director | A | +7,128 deriv. | — |
| 2026-08-21 | Mark McKechnie | See Remarks | MIXED | — | −$3.33M |
| 2026-08-20 | Haiping Dun | Director | MIXED | — | −$377.67K |
| 2026-07-06 | David H Wang | See Remarks | A | — | — |
| 2026-06-05 | Sotheara Cheav | See remarks | MIXED | — | −$1.33M |
| 2026-06-05 | David H Wang | See Remarks | MIXED | — | −$8.74M |
| 2026-05-21 | Haiping Dun | Director | MIXED | — | −$303.11K |
| 2026-04-21 | Charles C Pappis | Director | MIXED | — | −$114.10K |
| 2026-03-13 | David H Wang | See Remarks | MIXED | — | −$5.04M |
| 2026-03-13 | Mark McKechnie | See Remarks | MIXED | — | −$2.91M |
| 2026-03-12 | Tracy Liu | Director | MIXED | — | −$2.79M |
| 2026-03-11 | Haiping Dun | Director | MIXED | — | −$189.36K |
| 2026-03-09 | Charles C Pappis | Director | MIXED | — | −$104.55K |
| 2026-03-09 | Lisa Feng | See remarks | MIXED | — | −$1.30M |
| 2026-02-06 | David H Wang | See Remarks | A | — | — |
| 2025-12-08 | Mark McKechnie | See Remarks | MIXED | — | −$479.07K |
| 2025-12-05 | David H Wang | See Remarks | MIXED | — | −$4.23M |
| 2025-12-04 | Fuping Chen | See remarks | MIXED | — | −$3.77M |
| 2025-11-14 | Haiping Dun | Director | G | −755,090 | — |
| 2025-11-14 | Lisa Feng | See remarks | MIXED | — | −$829.95K |
| 2025-10-29 | David H Wang | See Remarks | A | — | — |
| 2025-09-30 | David H Wang | See Remarks | M | +130,000 | +$130.00K |
| 2025-09-19 | Sotheara Cheav | See remarks | MIXED | — | −$211.10K |
| 2025-09-19 | Tracy Liu | Director | MIXED | — | −$480.00K |
| 2025-09-19 | Jian Wang | See remarks | MIXED | — | −$882.00K |
| 2025-09-05 | David H Wang | See Remarks | MIXED | — | −$3.33M |
| 2025-08-26 | Sotheara Cheav | See remarks | MIXED | — | −$179.66K |
| 2025-08-26 | Jian Wang | See remarks | MIXED | — | −$1.52M |
| 2025-08-14 | Tracy Liu | Director | A | +20,000 deriv. | — |
| 2025-08-14 | Charles C Pappis | Director | A | +20,000 deriv. | — |
| 2025-08-14 | Haiping Dun | Director | A | +20,000 deriv. | — |
| 2025-07-17 | Tracy Liu | Director | MIXED | — | −$435.00K |
| 2025-07-09 | Lisa Feng | See remarks | MIXED | — | −$336.00K |
| 2025-06-26 | Lisa Feng | See remarks | MIXED | — | −$306.00K |
| 2025-05-23 | David H Wang | See Remarks | MIXED | — | −$2.88M |
| 2025-05-21 | Charles C Pappis | Director | A | +10,000 deriv. | — |
| 2025-05-16 | Mark McKechnie | See Remarks | MIXED | — | −$294.30K |
| 2025-03-19 | Chenming Hu | Director | Sell | −163,308 | −$4.90M |
| 2025-03-18 | Haiping Dun | Director | Sell | −9,518 | −$275.98K |
| 2025-03-14 | Mark McKechnie | See Remarks | MIXED | — | −$327.30K |
| 2025-03-13 | David H Wang | See Remarks | Sell | −131,250 | −$3.55M |
| 2025-03-12 | Haiping Dun | Director | Sell | −15,001 | −$398.13K |
| 2025-03-05 | David H Wang | See Remarks | MIXED | +205,952 | −$5 |
| 2025-03-05 | Haiping Dun | Director | MIXED | +24,519 | −$3 |
| 2025-02-10 | Mark McKechnie | See Remarks | MIXED | — | −$246.00K |
| 2025-02-10 | Sotheara Cheav | See remarks | MIXED | — | −$205.87K |
| 2024-12-03 | David H Wang | See Remarks | Sell | −56,250 | −$981.00K |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| David H Wang | See Remarks | 1,422,709 | $79.80M |
| Haiping Dun | Director | 758,890 | $42.57M |
| Jian Wang | See remarks | 253,158 | $14.20M |
| Tracy Liu | Director | 110,772 | $6.21M |
| Sotheara Cheav | See remarks | 101,649 | $5.70M |
| Chenming Hu | Director | 100,002 | $5.61M |
| Lisa Feng | See remarks | 65,001 | $3.65M |
| Mark McKechnie | See Remarks | 42,474 | $2.38M |
| Charles C Pappis | Director | 5,000 | $280.45K |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the ACMR quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.