Haiping Dun - SEC Form 4 Insider Trading Activity
Summary
Updated Aug 3, 2026
Haiping Dun has filed 1 SEC Form 4 filing across 1 company in the last 90 days - selling. Lifetime open-market sales: $1.17M.
Profile
Haiping Dun is a corporate insider at ACM Research, Inc. (ACMR). Dun has reported 7 insider filings with the SEC since 2024. The most recent filing was in May 2026.
| Role | Insider |
|---|---|
| Notability | 20/100 |
Board memberships
- ACM Research, Inc.
Trading Pattern
InsiderAlpha's records for Haiping Dun go back to 2024: 7 primary Form 4 filings, an average of 2.3 per year. 12 recorded transactions carry a Rule 10b5-1 flag, meaning they were pre-scheduled under a written trading plan rather than discretionary.
Career & Filing History
Every role Haiping Dun has reported on a Form 4, reconstructed from the filings themselves - reporting insiders must state their relationship to the issuer (officer title, director seat, or 10% ownership) on every filing.
- Insider at ACM Research, Inc. (ACMR) - 7 filings, 2024 to 2026
Recent Transactions
| Date | Ticker | Company | Code | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 2026-05-21 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 1.9K | $67.54 | $125K |
| 2026-05-21 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 1.3K | $67.21 | $88K |
| 2026-05-21 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 500 | $65.09 | $33K |
| 2026-05-21 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 1.3K | $63.84 | $85K |
| 2026-05-21 | ACMR | ACM Research, Inc. | M - Option exercise [10b5-1] | 5.0K | $5.60 | $28K |
| 2026-03-11 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 900 | $43.94 | $40K |
| 2026-03-11 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 4.1K | $43.37 | $178K |
| 2026-03-11 | ACMR | ACM Research, Inc. | M - Option exercise [10b5-1] | 5.0K | $5.60 | $28K |
| 2025-11-14 | ACMR | ACM Research, Inc. | G - Bona-fide gift | 755.1K | $0.00 | |
| 2024-12-03 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 19.1K | $17.43 | $332K |
| 2024-11-26 | ACMR | ACM Research, Inc. | S - Open-market sale [10b5-1] | 15.0K | $19.12 | $287K |
| 2024-11-18 | ACMR | ACM Research, Inc. | F - Tax withholding / forfeiture | 942 | $18.59 | $18K |
| 2024-11-18 | ACMR | ACM Research, Inc. | M - Option exercise | 35.0K | $0.50 | $18K |
Companies - Last 90 Days
- ACM Research, Inc. (ACMR) - 1 filing, last 2026-05-21
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades at the companies Haiping Dun has recently filed at. Multiple unrelated insiders buying the same stock within a short window - cluster buying - has historically been one of the strongest Form 4 signals.
- David H. Wang - $21.81M of ACMR open-market activity in the last 12 months
- Mark McKechnie - $4.49M of ACMR open-market activity in the last 12 months
- Fuping Chen - $3.98M of ACMR open-market activity in the last 12 months
- Tracy Liu - $3.35M of ACMR open-market activity in the last 12 months
- Jian Wang - $2.91M of ACMR open-market activity in the last 12 months
- Lisa Feng - $2.44M of ACMR open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
- Steve Handy
- Hanwha Aerospace Co., Ltd.
- Stayce D. Harris
- Harrison Street Real Assets Fund LLC
- Haveli Investments, L.P.
- Stephen J. Hemsley
- Jeffrey Robert Hernandez
- Patrick J. Heron
Frequently Asked Questions
Who is Haiping Dun?
Haiping Dun is a corporate insider at ACM Research, Inc. (ACMR). Dun has reported 7 insider filings with the SEC since 2024. The most recent filing was in May 2026.…
How many SEC Form 4 filings has Haiping Dun submitted recently?
1 primary Form 4 filing in the last 90 days, covering 1 company.
Has Haiping Dun been buying or selling stock?
Recorded transactions: 0 open-market purchases and 8 open-market sales ($1.17M) across all tracked filings.
Where can I see all of Haiping Dun's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
Learn More
Open the live Haiping Dun profile on InsiderAlpha for real-time alerts, AI-scored trade ideas, and full transaction history.