Form4insider filings, from the source

Company · CIK 0001680062 · SIC 3559 — Special Industry Machinery, NEC · Nasdaq

ACM Research, Inc. · ACMR

Insider activity reported against this company. All insider holders · On EDGAR ↗

1M3M6M1Y2YAll datashares as filed — not split-adjusted
Open-market buys & salesbuys $0 · 0sales $25.7M · 5net −$25.7M
$10k$10k$1M$1M$100M$100MbuyssalesJun 2Jun 18Jul 5Jul 21Aug 7Aug 23Sep 9

Reported at this company — common stock

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Sep 8, 2026 SForm 4 →Sep 10, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner140,000$75.93$10,630,010802,708−14.9%10b5-1
Sep 8, 2026 MForm 4 →Sep 10, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner140,000$1.00$140,000872,708—10b5-1
Aug 20, 2026 SForm 4 →Aug 21, 9:30 pm EDTMark McKechnieSee Remarks55,199$77.27$4,264,971900−98.4%10b5-1
Aug 20, 2026 MForm 4 →Aug 21, 9:30 pm EDTMark McKechnieSee Remarks55,199$16.95$935,82956,099—10b5-1
Aug 18, 2026 SForm 4 →Aug 20, 4:30 pm EDTHaiping DunDirector5,000$81.13$405,6700−100%10b5-1
Aug 18, 2026 MForm 4 →Aug 20, 4:30 pm EDTHaiping DunDirector5,000$5.60$28,0005,000—10b5-1
Jun 4, 2026 SForm 4 →Jun 5, 9:00 pm EDTSotheara CheavSee remarks18,750$84.58$1,585,923100,002−15.8%10b5-1
Jun 4, 2026 MForm 4 →Jun 5, 9:00 pm EDTSotheara CheavSee remarks18,750$13.89$260,438105,401—10b5-1
Jun 3, 2026 SForm 4 →Jun 5, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner100,002$88.35$8,835,388802,708−11.1%10b5-1
Jun 3, 2026 MForm 4 →Jun 5, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner100,002$1.00$100,002842,710—10b5-1
Aug 30, 2018 MForm 4 →Aug 31, 4:37 pm EDTChenming HuDirector30,000$3.00$90,00030,000— plan?
Jun 29, 2018 MForm 4 →Jul 3, 4:36 pm EDTDavid H WangSee Remarks, Director, 10% Owner15,279$3.00$45,83715,279— plan?
Jun 28, 2018 MForm 4 →Jun 29, 4:35 pm EDTTracy LiuDirector16,667$3.00$50,00119,067— plan?
Jun 4, 2018 CForm 4 →Jul 31, 4:35 pm EDTSotheara CheavSee remarks25,667——33,334— plan? late
Apr 2, 2018 XForm 4 →Jul 31, 4:43 pm EDTJian WangSee remarks397,502$7.50$2,981,265481,888— plan? late
Jan 31, 2018 MForm 4 →May 17, 4:36 pm EDTFufa ChenSee Remarks56,249$1.06$59,373129,583— plan? late

Reported at this company — derivatives (options, RSUs, warrants)

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Sep 8, 2026 MForm 4 →Sep 10, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner140,000——130,000—10b5-1
Aug 20, 2026 MForm 4 →Aug 21, 9:30 pm EDTMark McKechnieSee Remarks55,199——215,000—10b5-1
Aug 18, 2026 MForm 4 →Aug 20, 4:30 pm EDTHaiping DunDirector5,000——45,000—10b5-1
Aug 12, 2026 AForm 4 →Aug 26, 9:30 pm EDTCharles C PappisDirector7,128——728— late
Aug 12, 2026 AForm 4 →Aug 26, 9:30 pm EDTTracy LiuDirector7,128——728— late
Aug 12, 2026 AForm 4 →Aug 26, 9:30 pm EDTHaiping DunDirector7,128——728— late
Jun 4, 2026 MForm 4 →Jun 5, 9:00 pm EDTSotheara CheavSee remarks18,750——37,500—10b5-1
Jun 3, 2026 MForm 4 →Jun 5, 4:30 pm EDTDavid H WangSee Remarks, Director, 10% Owner100,002——270,000—10b5-1
May 13, 2026 AForm 4 →Jul 6, 9:00 pm EDTDavid H WangSee Remarks, Director, 10% Owner6,208——6,208— late
Aug 30, 2018 MForm 4 →Aug 31, 4:37 pm EDTChenming HuDirector30,000——53,334—
Aug 1, 2018 AForm 4 →Oct 23, 4:35 pm EDTJian WangSee remarks40,000——40,000— late
Aug 1, 2018 AForm 4 →Oct 23, 4:35 pm EDTSotheara CheavSee remarks40,000——40,000— late
Jun 29, 2018 MForm 4 →Jul 3, 4:36 pm EDTDavid H WangSee Remarks, Director, 10% Owner15,279——0—
Jun 28, 2018 MForm 4 →Jun 29, 4:35 pm EDTTracy LiuDirector16,667——0—
Jun 4, 2018 CForm 4 →Jul 31, 4:35 pm EDTSotheara CheavSee remarks25,667——0— late
Apr 2, 2018 XForm 4 →Jul 31, 4:43 pm EDTJian WangSee remarks397,502——0— late
Jan 31, 2018 MForm 4 →May 17, 4:36 pm EDTFufa ChenSee Remarks56,249——10,419— late