Dun Haiping
Director · ACMR
As of 2026-09-16, Dun Haiping has 25 Form 4 transactions on record across 1 company — 18 in the trailing 12 months.
Everything this person has disclosed to the SEC on Form 4 — across every company they file for — reconstructed from the public record. A filing history, not a tip sheet.
Pattern in the record: open-market sales filed in March in multiple years since 2025 — a recurring calendar cadence, more consistent with scheduled activity than a one-off decision.
Reconstructed holdings
- Direct $2.9M
- Indirect $0
| ACMR | direct | 45,000 sh | $2.9M |
Reconstructed from this person's own Form 4 filings — the total each filing reported owning afterward, priced at the close on the as-of date shown. A filed position can lag the real one.
Direct and indirect holdings (e.g. through a trust or fund) are tagged separately, as filed.
Trades by company
Filing ledger
| Date | Company | Action | Shares @ price | Value | Ownership Δ | Owned after | Filing |
|---|---|---|---|---|---|---|---|
| 2026-08-18 | ACMR | Sale | 3,400 @ $81.31 | $276K | −89.5% of holding | 400 | Form 4 |
| 2026-08-18 | ACMR | Sale | 1,200 @ $80.29 | $96K | −24.0% of holding | 3,800 | Form 4 |
| 2026-08-18 | ACMR | Sale | 400 @ $82.17 | $33K | −100.0% of holding | 0 | Form 4 |
| 2026-05-19 | ACMR | Sale | 1,858 @ $67.54 | $125K | −100.0% of holding | 0 | Form 4 |
| 2026-05-19 | ACMR | Sale | 1,309 @ $67.21 | $88K | −41.3% of holding | 1,858 | Form 4 |
| 2026-05-19 | ACMR | Sale | 1,333 @ $63.84 | $85K | −26.7% of holding | 3,667 | Form 4 |
| 2026-05-19 | ACMR | Sale | 500 @ $65.09 | $33K | −13.6% of holding | 3,167 | Form 4 |
| 2026-03-09 | ACMR | Sale | 4,100 @ $43.37 | $178K | −82.0% of holding | 900 | Form 4 |
| 2026-03-09 | ACMR | Sale | 900 @ $43.94 | $40K | −100.0% of holding | 0 | Form 4 |
| 2025-03-14 | ACMR | Sale | 7,062 @ $29.23 | $206K | −0.9% of holding | 755,090 | Form 4 |
| 2025-03-14 | ACMR | Sale | 2,456 @ $28.32 | $70K | −0.3% of holding | 762,152 | Form 4 |
| 2025-03-10 | ACMR | Sale | 15,001 @ $26.54 | $398K | −1.9% of holding | 764,608 | Form 4 |
13 award / exercise / gift records — not counted as purchases
| Date | Company | Action | Shares | Owned after | Filing |
|---|---|---|---|---|---|
| 2026-08-18 | ACMR | Option exercise | 5,000 | 5,000 | Form 4 |
| 2026-08-18 | ACMR | Option exercise | 5,000 | 45,000 | Form 4 |
| 2026-08-12 | ACMR | Award / grant | 6,400 | 6,400 | Form 4 |
| 2026-08-12 | ACMR | Award / grant | 728 | 728 | Form 4 |
| 2026-05-19 | ACMR | Option exercise | 5,000 | 5,000 | Form 4 |
| 2026-05-19 | ACMR | Option exercise | 5,000 | 50,000 | Form 4 |
| 2026-03-09 | ACMR | Option exercise | 5,000 | 5,000 | Form 4 |
| 2026-03-09 | ACMR | Option exercise | 5,000 | 55,000 | Form 4 |
| 2025-11-12 | ACMR | Gift | 755,090 | 0 | Form 4 |
| 2025-08-12 | ACMR | Award / grant | 20,000 | 20,000 | Form 4 |
| 2025-03-03 | ACMR | Withheld for tax | 482 | 779,609 | Form 4 |
| 2025-03-03 | ACMR | Option exercise | 25,001 | 780,091 | Form 4 |
| 2025-03-03 | ACMR | Option exercise | 25,001 | 0 | Form 4 |
Source: SEC Form 4 filings. Each row links to its original filing.
Research tool, not investment advice — historical frequencies, not recommendations. A product of Marovel Technologies LLC. Full terms.