Acm Research, Inc.
A maker of wet-cleaning machines that keep semiconductor chips free of tiny particles during manufacturing, sold largely to chip fabs in mainland China under technologies like SAPS, TEBO, and Tahoe. It also builds electroplating, furnace, and packaging tools. Founded in 1998 in Silicon Valley by Dr. David Wang, it pivoted from stress-free copper polishing to cleaning after early tools struggled commercially. Its name "ACM" originally stood for "Advanced Copper Materials," a nod to its first copper-polishing ambition.
Sold 1.10M
Sold 520.0K
Sold 1.10M
Granted 2.25M · Sold 1.87M
Granted 502.3K · Sold 474.2K
Granted 243.3K · Sold 242.5K
Granted 56.2K
Granted 170.2K · Sold 133.5K
Granted 215.8K · Sold 235.2K
Granted 117.8K · Sold 203.3K
Granted 174.7K · Sold 165.0K
Granted 10.0K · Sold 10.0K
Granted 360.6K · Sold 360.3K
Granted 255.0K · Sold 255.0K
| Insider | Stake change | Holds now | Granted / vested | Bought | Sold |
|---|---|---|---|---|---|
| Shanghai Pudong Science & Technology Investment Group Co., Ltd. +1 co-filer10% owner, Possible member of 10% group · 8 transactions | — | 5.70Mas of Oct 2024 | — | — | 1.10M |
| Xiang YinanDirector · 19 transactions | — | 2.86Mas of Aug 2021 | — | — | 520.0K |
| Xing XiaoDirector · 8 transactions | — | 2.34Mas of Oct 2024 | — | — | 1.10M |
| Wang David HSee Remarks, Director, 10% owner · 91 transactions | — | 1.75M | 2.25M | — | 1.87M |
| Dun HaipingDirector · 69 transactions | — | 855.1K | 502.3K | — | 474.2K |
| Wang JianSee remarks · 20 transactions | — | 253.2K | 243.3K | — | 242.5K |
| Chen FufaSee Remarks · 2 transactions | — | 129.6Kas of Jan 2018 | 56.2K | — | — |
| Liu TracyDirector · 24 transactions | — | 114.1K | 170.2K | — | 133.5K |
| Cheav SothearaSee remarks · 50 transactions | — | 100.0K | 215.8K | — | 235.2K |
| Hu ChenmingDirector · 11 transactions | — | 100.0Kas of Mar 2025 | 117.8K | — | 203.3K |
| Feng LisaSee remarks · 30 transactions | — | 50.0K | 174.7K | — | 165.0K |
| Pappis Charles CDirector · 4 transactions | — | 5.0K | 10.0K | — | 10.0K |
| McKechnie MarkSee Remarks · 66 transactions | — | 900 | 360.6K | — | 360.3K |
| Chen FupingSee remarks · 10 transactions | — | 0 | 255.0K | — | 255.0K |
Select a row to see that insider’s individual transactions. Sum of the holdings confirmed in the 12 months before this insider's last filing. A Form 4 reports a holding per line — held directly, or through a named trust, partnership or foundation, and in each share class separately — never a person’s total. Lines not restated in that time are left out and shown apart: an active filer restates what they still hold, so a line they did not restate is more often an entity since renamed, whose shares a successor line reports too. An amber marker means some were left out.
Net open-market activity over all recorded history: -6.67M shares. Grants, option exercises and tax withholding are excluded — they are compensation mechanics, not decisions to buy or sell.