As of August 04, 2026, the three largest insider holders of ACMR are Xiao Xing (Director, 2.34Mn shares), Science Technology Venture Capital (Group) Co., Ltd. Shanghai (TenPercentOwner, 2.34Mn shares), Yinan Xiang (Director, 1.15Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Science Technology Venture Capital (Group) Co., Ltd. Shanghai | TenPercentOwner, Other | 2,338,510 | 0 | 2,338,510 | 32.3% | 08 Oct, 2024 |
| 2 | Xiao Xing | Director | 0 | 2,338,510 | 2,338,510 | 32.3% | 08 Oct, 2024 |
| 3 | Yinan Xiang | Director | 0 | 1,146,170 | 1,146,170 | 15.8% | 24 Aug, 2021 |
| 4 | David H Wang | Director, Officer, TenPercentOwner | 802,708 | 0 | 802,708 | 11.1% | 13 Mar, 2026 |
| 5 | Jian Wang | Officer | 253,158 | 0 | 253,158 | 3.5% | 19 Sep, 2025 |
| 6 | Tracy Liu | Director | 110,772 | 0 | 110,772 | 1.5% | 12 Mar, 2026 |
| 7 | Chenming Hu | Director | 100,002 | 0 | 100,002 | 1.4% | 19 Mar, 2025 |
| 8 | Sotheara Cheav | Officer | 100,002 | 0 | 100,002 | 1.4% | 19 Sep, 2025 |
| 9 | Lisa Feng | Officer | 50,001 | 0 | 50,001 | 0.7% | 09 Mar, 2026 |
| 10 | Mark Mckechnie | Officer | 900 | 0 | 900 | 0.0% | 13 Mar, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 17 Apr, 2026 | Charles C Pappis | Director | Acquired M | 5,000 | $29.18 | $145.90K | 5,000 | Direct |
| 17 Apr, 2026 | Charles C Pappis | Director | Disposed S | 5,000 | $52.00 | $260.00K | 0 | Direct |
| 17 Apr, 2026 | Charles C Pappis | Director | Disposed M | 5,000 | $0.00 | $0 | 0 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Acquired M | 60,000 | $13.89 | $833.40K | 60,900 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Acquired M | 60,000 | $1.00 | $60.00K | 862,708 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Acquired M | 60,000 | $13.89 | $833.40K | 60,900 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Acquired M | 60,000 | $13.89 | $833.40K | 60,900 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Acquired M | 60,000 | $1.00 | $60.00K | 862,708 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Acquired M | 60,000 | $1.00 | $60.00K | 862,708 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Acquired M | 60,000 | $1.00 | $60.00K | 862,708 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Acquired M | 60,000 | $13.89 | $833.40K | 60,900 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Disposed S | 55,373 | $47.89 | $2.65Mn | 807,335 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Disposed S | 55,373 | $47.89 | $2.65Mn | 807,335 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Disposed S | 11,910 | $44.89 | $534.64K | 48,990 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Disposed S | 55,373 | $47.89 | $2.65Mn | 807,335 | Direct |
| 11 Mar, 2026 | David H Wang | Director, Officer, TenPercentOwner | Disposed S | 55,373 | $47.89 | $2.65Mn | 807,335 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Disposed S | 11,910 | $44.89 | $534.64K | 48,990 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Disposed S | 11,910 | $44.89 | $534.64K | 48,990 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Disposed S | 11,910 | $44.89 | $534.64K | 48,990 | Direct |
| 12 Mar, 2026 | Mark Mckechnie | Officer | Disposed S | 47,108 | $45.74 | $2.15Mn | 1,882 | Direct |