13D·WATCH Activist + Insider Intelligence Live feed Blog About Pricing
SCHEDULE 13G Filed 2026-07-31 Event — SEC 0002100121-26-000871 →

VANGUARD PORTFOLIO MANAGEMENT LLC → ACM Research Inc ACMR

Stake: — Shares: — CUSIP: 00108J109 Class: Common Stock
Composite Decision Signal · PASS (LOW BASE-RATE EDGE) Conviction Score: 4/100
  • Passive Schedule 13G filer baseline
  • Net insider selling ($4,264,971 Code-S in ±30d)
  • Held by 1 tracked 13F institutional manager
  • 13 NPORT-P mutual funds holding CUSIP

Item 4 — Purpose of Transaction

Not extracted from this filing — typically because it's an amendment (13D/A) and Item 4 is unchanged from the parent filing. Read the raw SEC filing →

Cross-References

Insider Activity (last 365d)
20 transactions
6 buys · 10 sales · 4 awards/exercises
Issuer Cluster
3 13D/G filings on this issuer
2 other filings besides this one
Filer Track Record
17 filings by this filer
16 other filings in the data moat
Short Interest · settle 2026-10-15
DTC 2.58
3,482,683 shares short · -14.1% vs prior

Institutional Consensus · 2025-12-31

Held by elite portfolio managers
1 holder · $6.17M
Point72 Asset Mgmt

Form 4 Insider Transactions · last 365d

DateInsiderRoleTypeSharesPriceValue
2026-08-20 McKechnie Mark officer Option exercise 30,199 $19.49 $589K
2026-08-20 McKechnie Mark officer Option exercise 25,000 $13.89 $347K
2026-08-20 McKechnie Mark officer Sale 13,625 $76.34 $1.04M
2026-08-20 McKechnie Mark officer Sale 30,365 $77.45 $2.35M
2026-08-20 McKechnie Mark officer Sale 11,209 $77.89 $873K
2026-08-12 Pappis Charles C director Award 6,400 $81.26 $520K
2026-08-12 Pappis Charles C director Award 728 $96.13 $70K
2026-08-12 Liu Tracy director Award 6,400 $81.26 $520K
2026-08-12 Liu Tracy director Award 728 $96.13 $70K
2026-08-12 Dun Haiping director Award 6,400 $81.26 $520K
2026-08-12 Dun Haiping director Award 728 $96.13 $70K
2026-06-05 Cheav Sotheara officer Option exercise 5,399 $13.89 $75K
2026-06-05 Cheav Sotheara officer Sale 2,384 $81.73 $195K
2026-06-05 Cheav Sotheara officer Sale 968 $82.61 $80K
2026-06-05 Cheav Sotheara officer Sale 400 $84.01 $34K
2026-06-05 Cheav Sotheara officer Sale 1,647 $85.41 $141K
2026-06-04 Cheav Sotheara officer Option exercise 13,351 $13.89 $185K
2026-06-04 Cheav Sotheara officer Sale 1,300 $84.08 $109K
2026-06-04 Cheav Sotheara officer Sale 9,212 $85.11 $784K
2026-06-04 Cheav Sotheara officer Sale 2,839 $85.77 $244K

Other 13D/G Filings on ACM Research Inc

FiledFormFilerStakeShares
2024-10-08 SC Shanghai Science & Technology Venture Capital (Group) Co., Ltd. — — view →
2023-07-18 SC Shanghai Science & Technology Venture Capital (Group) Co., Ltd. — — view →

Other Filings by VANGUARD PORTFOLIO MANAGEMENT LLC

FiledFormIssuerStakeShares
2026-10-30 SCHEDULE 13G A10 Networks Inc — — view →
2026-10-30 SCHEDULE 13G ADI Global Distribution Inc — — view →
2026-10-30 SCHEDULE 13G Alnylam Pharmaceuticals Inc — — view →
2026-09-03 SCHEDULE 13G ZIONS BANCORPORATION, NATIONAL ASSOCIATION /UT/ — — view →
2026-09-03 SCHEDULE 13G BellRing Brands, Inc. — — view →
2026-09-03 SCHEDULE 13G CAL-MAINE FOODS INC — — view →
2026-09-03 SCHEDULE 13G Pediatrix Medical Group, Inc. — — view →
2026-07-31 SCHEDULE 13G Atmus Filtration Technologies Inc — — view →
2026-07-31 SCHEDULE 13G Autodesk Inc — — view →
2026-07-31 SCHEDULE 13G Bright Horizons Family Solutions Inc — — view →
2026-07-31 SCHEDULE 13G Buckle Inc/The — — view →
2026-07-31 SCHEDULE 13G AGNT Inc — — view →
2026-07-31 SCHEDULE 13G Argan Inc — — view →
2026-07-31 SCHEDULE 13G Ashland Inc — — view →
2026-07-31 SCHEDULE 13G Alignment Healthcare Inc — — view →
2026-07-31 SCHEDULE 13G Astrana Health Inc — — view →

Want this depth on every filing the moment it hits SEC EDGAR?

Free $0 (48h-delayed alerts) · Individual $49/mo (real-time) · Team & API $199/mo · Enterprise.

See pricing →