ACMR (ACM Research, Inc. Class A Common Stock)
Insider Trading Activity
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.
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.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-26 | Charles C Pappis | Director | A | — | — |
| 2026-08-26 | Tracy Liu | Director | A | — | — |
| 2026-08-26 | Haiping Dun | Director | A | — | — |
| 2026-08-21 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2026-08-20 | Haiping Dun | Director | MIXED | — | — |
| 2026-07-06 | David H Wang | See Remarks | A | — | — |
| 2026-06-05 | Sotheara Cheav | See remarks | MIXED | — | — |
| 2026-06-05 | David H Wang | See Remarks | MIXED | — | — |
| 2026-05-21 | Haiping Dun | Director | MIXED | — | — |
| 2026-04-21 | Charles C Pappis | Director | MIXED | — | — |
| 2026-03-13 | David H Wang | See Remarks | MIXED | — | — |
| 2026-03-13 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2026-03-12 | Tracy Liu | Director | MIXED | — | — |
| 2026-03-11 | Haiping Dun | Director | MIXED | — | — |
| 2026-03-09 | Charles C Pappis | Director | MIXED | — | — |
| 2026-03-09 | Lisa Feng | See remarks | MIXED | — | — |
| 2026-02-06 | David H Wang | See Remarks | A | — | — |
| 2025-12-08 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2025-12-05 | David H Wang | See Remarks | MIXED | — | — |
| 2025-12-04 | Fuping Chen | See remarks | MIXED | — | — |
| 2025-11-14 | Haiping Dun | Director | G | — | — |
| 2025-11-14 | Lisa Feng | See remarks | MIXED | — | — |
| 2025-10-29 | David H Wang | See Remarks | A | — | — |
| 2025-09-30 | David H Wang | See Remarks | M | — | — |
| 2025-09-19 | Sotheara Cheav | See remarks | MIXED | — | — |
| 2025-09-19 | Tracy Liu | Director | MIXED | — | — |
| 2025-09-19 | Jian Wang | See remarks | MIXED | — | — |
| 2025-09-05 | David H Wang | See Remarks | MIXED | — | — |
| 2025-08-26 | Sotheara Cheav | See remarks | MIXED | — | — |
| 2025-08-26 | Jian Wang | See remarks | MIXED | — | — |
| 2025-08-14 | Tracy Liu | Director | A | — | — |
| 2025-08-14 | Charles C Pappis | Director | A | — | — |
| 2025-08-14 | Haiping Dun | Director | A | — | — |
| 2025-07-17 | Tracy Liu | Director | MIXED | — | — |
| 2025-07-09 | Lisa Feng | See remarks | MIXED | — | — |
| 2025-06-26 | Lisa Feng | See remarks | MIXED | — | — |
| 2025-05-23 | David H Wang | See Remarks | MIXED | — | — |
| 2025-05-21 | Charles C Pappis | Director | A | — | — |
| 2025-05-16 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2025-03-19 | Chenming Hu | Director | Sell | — | — |
| 2025-03-18 | Haiping Dun | Director | Sell | — | — |
| 2025-03-14 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2025-03-13 | David H Wang | See Remarks | Sell | — | — |
| 2025-03-12 | Haiping Dun | Director | Sell | — | — |
| 2025-03-05 | David H Wang | See Remarks | MIXED | — | — |
| 2025-03-05 | Haiping Dun | Director | MIXED | — | — |
| 2025-02-10 | Mark McKechnie | See Remarks | MIXED | — | — |
| 2025-02-10 | Sotheara Cheav | See remarks | MIXED | — | — |
| 2024-12-03 | David H Wang | See Remarks | Sell | — | — |
| 2024-12-03 | Haiping Dun | Director | Sell | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | 10%+ Owner | 6,788,934 | — |
| — | 10%+ Owner | 6,191,899 | — |
| — | Director | 3,438,510 | — |
| — | Director | 2,530,901 | — |
| — | See Remarks | 1,462,711 | — |
| — | Director | 758,890 | — |
| — | See Remarks | 320,004 | — |
| — | See remarks | 253,158 | — |
| — | Director | 110,772 | — |
| — | See remarks | 101,649 | — |
| — | Director | 100,002 | — |
| — | See remarks | 65,001 | — |
| — | See Remarks | 42,474 | — |
| — | Director | 5,000 | — |
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.