ACMR

ACM Research, Inc.

NasdaqIndustrialsSpecial Industry Machinery, NEC

Insider activity for last month from 08/11 to 09/11. Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.

Latest filingSep 10, 2026Most recent Form 4
Total buying$00 buys
Total selling$1.53B15 sells
Net open-market-$1.53B5 insiders
Open-market mix
Buy vs sell distribution by transaction count
15 transactions
0 buys0%·100%15 sells

Insider activity report

Monthly open-market purchase and sale counts
Buys Sells
1050-5-10transactionsAug 2026 sells: 6 transactions · $467M6AugSep 2026 sells: 9 transactions · $1.06B9Sep

Transaction codes

By Form 4 transaction code in selected period
31transactions
  • S · Open-market sells · dominant15 · 48%
  • M · Option exercise10 · 32%
  • A · Grants / awards6 · 19%

Activity by reported role

A joint filing can contribute to multiple roles
31transactions
  • SR · dominant20 · 65%
  • Director11 · 35%

Distinct insiders active

Reporting-owner CIKs by month · peak Aug 2026 (4)
Aug 2026Sep 2026
5distinct insiders in 2 months

Reported Holdings After

Separated by insider, security, and ownership type
Wang David HClass A Common Stock · Direct
872.7k802.7kSep 08, 2026 · 867,905 shares owned afterSep 08, 2026 · 816,531 shares owned afterSep 08, 2026 · 804,208 shares owned afterSep 08, 2026 · 802,708 shares owned afterSep 08, 2026 · 872,708 shares owned afterSep 09, 2026 · 802,708 shares owned afterSep 09, 2026 · 803,808 shares owned afterSep 09, 2026 · 872,708 shares owned afterSep 09, 2026 · 839,215 shares owned afterSep 09, 2026 · 820,281 shares owned afterSep 09, 2026 · 808,615 shares owned afterSep 08, 2026Sep 09, 2026
808,615Sep 09, 2026
McKechnie MarkClass A Common Stock · Direct
56.1k900Aug 20, 2026 · 56,099 shares owned afterAug 20, 2026 · 42,474 shares owned afterAug 20, 2026 · 31,099 shares owned afterAug 20, 2026 · 12,109 shares owned afterAug 20, 2026 · 900 shares owned afterAug 20, 2026Aug 20, 2026
900Aug 20, 2026
Dun HaipingClass A Common Stock · Direct
5.0k0Aug 18, 2026 · 3,800 shares owned afterAug 18, 2026 · 0 shares owned afterAug 18, 2026 · 400 shares owned afterAug 18, 2026 · 5,000 shares owned afterAug 18, 2026Aug 18, 2026
5,000Aug 18, 2026
Dun HaipingStock Option · Direct
45.0k6.4kAug 12, 2026 · 6,400 shares owned afterAug 18, 2026 · 45,000 shares owned afterAug 12, 2026Aug 18, 2026
45,000Aug 18, 2026
McKechnie MarkStock Option · Direct
215.0k31.3kAug 20, 2026 · 31,250 shares owned afterAug 20, 2026 · 215,000 shares owned afterAug 20, 2026Aug 20, 2026
215,000Aug 20, 2026
Wang David HStock Option · Direct
200.0k130.0kSep 08, 2026 · 200,000 shares owned afterSep 09, 2026 · 130,000 shares owned afterSep 08, 2026Sep 09, 2026
130,000Sep 09, 2026
Dun HaipingRestricted Stock Units · Direct
728728Aug 12, 2026 · 728 shares owned afterAug 12, 2026Aug 12, 2026
728Aug 12, 2026
Liu TracyStock Option · Direct
6.4k6.4kAug 12, 2026 · 6,400 shares owned afterAug 12, 2026Aug 12, 2026
6,400Aug 12, 2026

These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.

Filing activity heatmap
Each cell is one day · intensity = transactions · buys green, sells red
0 active days
Aug 11Sep 11
LessMore

Filing detail checks

Secondary metrics for the selected period
Largest buy-
Largest sale$396M
10b5-1 detected25
Amended rows0

ACMR transaction history

Filters apply within this company and selected period by default
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TickerInsiderRoleTypeSharesValueCodeSignals90d returnFiledTrans date

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ACM Research, Inc. Insider Activity FAQ

SEC Form 4 context

Who recently reported transactions at ACM Research, Inc.?

Wang David H, Pappis Charles C, Liu Tracy, Dun Haiping, McKechnie Mark.

When was the latest reported open-market purchase?

No code-P purchase is available for this period.

When was the latest reported open-market sale?

Wang David H reported a sale on Sep 09, 2026 valued at $8.53M. Read the SEC filing.

What is the recent purchase and sale balance?

Net open-market selling in the selected period was $15,300,651.24. Sales can occur for many non-investment reasons.

Where can I see the original SEC filing?

Every transaction row and latest-activity fact links to its original SEC filing.

What do these Form 4 transaction codes mean?

P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.