Haiping Dun Sells $406K of ACM Research Inc (ACMR) — SEC Form 4, Aug 20, 2026
Open-Market Net Sale · SEC Form 4
−$405,670
10b5-1 Plan (Partial)
Equity Position
860K sh
860,090 → 860,090
Filing Lag
2 business days
within 2-day SEC deadline
Form 4 · Statement of Changes in Beneficial Ownership
Reporting Owner
| Name | Relationship |
|---|---|
| Haiping Dun CIK 0001721581 |
Director
|
Haiping Dun at ACM Research Inc
Full insider history
Bought (12 mo)
—
Sold (12 mo)
$954,144
More from this insider at ACM Research Inc
| 2026-08-27 | Award | — | View |
| 2026-05-21 | Sell | -$331,111 | View |
| 2026-03-11 | Sell | -$217,363 | View |
| 2025-11-14 | Gift/Other | — | View |
| 2025-08-14 | Award | — | View |
Non-Derivative Securities Transactions
| Title | Date | Type | Shares | Price | Net Total | Post-Txn | Ownership |
|---|---|---|---|---|---|---|---|
| Class A Common Stock | 2026-08-18 | M - Exercise 10b5-1 | 5,000 A | $5.60 | +$28,000 | 5,000 | Direct |
| Class A Common StockF1F2 | 2026-08-18 | S - Sale 10b5-1 | 1,200 D | $80.29 | -$96,348 | 3,800 | Direct |
| Class A Common StockF1F3 | 2026-08-18 | S - Sale 10b5-1 | 3,400 D | $81.31 | -$276,454 | 400 | Direct |
| Class A Common StockF1F4 | 2026-08-18 | S - Sale 10b5-1 | 400 D | $82.17 | -$32,868 | 0 | Direct |
Derivative Securities Transactions
| Title | Strike | Date | Type | Shares | Price | Expiration | Underlying | Ownership |
|---|---|---|---|---|---|---|---|---|
| Stock OptionF5 | $5.60 | 2026-08-18 | M - Exercise | 5,000 D | $0.00 | 2029-04-22 | 5,000 Class A Common Stock | Direct |
Non-Derivative Holdings
| Title | Shares Held | Ownership |
|---|---|---|
| Class A Common Stock | 100,000 | Indirect Dun Family GST Trust |
| Class A Common Stock | 755,090 | Indirect Haiping Dun & Chi-Pin H Dun Revocable Trust |
Footnotes (5)
- F1
- The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 13, 2025. Show more
- F2
- The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $79.89 to $80.77, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2), (3), and (4) to this Form 4. Show more
- F3
- The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $80.95 to $81.91, inclusive. Show more
- F4
- The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $81.97 to $82.33, inclusive. Show more
- F5
- The option is fully vested and exercisable. Show more
Related filings at ACM Research Inc
Institutional Holders
13F holders · Jun 30, 2026
379
institutional managers reporting a position
Largest by reported value
- Black Rock, Inc. $1.1B
- Vanguard Portfolio Management Llc $425M
- Vanguard Capital Management Llc $312M
5%+ Holders · 13D/G
2 filers
Other insiders at ACM Research Inc
-
David H Wang -$10.6M
-
Mark Mckechnie -$4.26M
-
Sotheara Cheav -$1.59M
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