Acm Research Inc (ACMR) insider trading
Recent insider transactions reported to the SEC on Form 4 — directors and officers buying or selling their own company’s stock. Sourced directly from public SEC filings, latest filed Sep 10, 2026.
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- Filings shown
- 9
- Open-market buys
- 0
- Open-market sells
- 33
Counts cover the 9 most recent Form 4 filings Tradune holds for ACMR (filed Jun 5 – Sep 10, 2026); the score below covers only the trailing 90 days (0 buys, 15 sells). No completed check of ACMR's Form 4 list on SEC EDGAR is on record yet; the latest ACMR filing Tradune holds was filed Sep 10, 2026. This is not guaranteed to be the complete record — see ACMR's full Form 4 filing history on SEC EDGAR.
Open-market activity, last 90 days
Purchases (Form 4 code P) and sales (code S) on the 6 filings Tradune holds for ACMR filed Aug 20 – Sep 10, 2026. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
15 open-market sales by Rule 10b5-1 checkbox
- On filings with the 10b5-1 box checked
- 15 sales· 200,199 sh
- checkbox disclosed
- On filings with the box not checked
- 0 sales· 0 sh
- not proof that no plan exists
- Not comparable
- 0 sales· 0 sh
- filed before Apr 1, 2023, or no checkbox value in the filing data
Counts are Form 4 lines as filed. The checkbox is one per filing, so every sale on a filing with the box checked is counted there even if only some of its transactions were under a plan; it records what the filer disclosed, and the three categories are not a judgement about why a sale was made.
| Insider | Buys | Sells | Shares bought | Shares sold | Value |
|---|---|---|---|---|---|
| David H. WangOfficer (see filing) | 0 | 9 | — | 140,000 | −$10,630,010 |
| Mark McKechnieOfficer (see filing) | 0 | 3 | — | 55,199 | −$4,264,971 |
| Haiping DunDirector | 0 | 3 | — | 5,000 | −$405,670 |
Value = shares × the price reported on each Form 4 (+ purchases, − sales); every open-market line in this window disclosed a price.
Summarises ~90 days of public SEC Form 4 activity — more distinct buyers, officer involvement and net buying score higher. A description of filing activity, not a rating or buy signal. How this score is computed →
How to read this: an open-market purchase (Form 4 code P) is a buy at the market price with the insider’s own money, as opposed to a grant, award or option exercise; an open-market sale is code S. When two or more distinct insiders report open-market purchases in the same 90-day window, this site labels that a cluster — a definition, not a forecast; see insider cluster buying. “Held after” is Form 4 Table I column 5; “Change” = shares ÷ holdings before the trade (held after − shares for an acquisition, held after + shares for a disposition).
Insider Buying at ACMR
No open-market insider purchases (Form 4 code P) were reported for ACMR between Jun 5, 2026 and Sep 10, 2026. The filings below may include other transaction types — sales, grants, option exercises, and tax withholding — shown for completeness; they are not open-market purchases.
Recent Form 4 filings
Source: SEC EDGAR Form 4 · transaction codes explained
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 33,493 | $73.80 | 839,215 | −3.8% | Sep 9, 2026 |
| Open-market sale 10b5-1 box checked | 4,807 | $76.73 | 803,808 | −0.6% | Sep 9, 2026 |
| Open-market sale 10b5-1 box checked | 1,100 | $77.59 | 802,708 | −0.1% | Sep 9, 2026 |
| Open-market sale 10b5-1 box checked | 18,934 | $74.67 | 820,281 | −2.3% | Sep 9, 2026 |
| Option exercise Stock Option | 70,000 | — | — | — | Sep 9, 2026 |
| Open-market sale 10b5-1 box checked | 11,666 | $75.58 | 808,615 | −1.4% | Sep 9, 2026 |
| Option exercise | 70,000 | $1.00 | 872,708 | +8.7% | Sep 9, 2026 |
| Open-market sale 10b5-1 box checked | 1,500 | $78.57 | 802,708 | −0.2% | Sep 8, 2026 |
| Open-market sale 10b5-1 box checked | 12,323 | $78.08 | 804,208 | −1.5% | Sep 8, 2026 |
| Open-market sale 10b5-1 box checked | 51,374 | $77.15 | 816,531 | −5.9% | Sep 8, 2026 |
| Open-market sale 10b5-1 box checked | 4,803 | $75.99 | 867,905 | −0.6% | Sep 8, 2026 |
| Option exercise | 70,000 | $1.00 | 872,708 | +8.7% | Sep 8, 2026 |
| Option exercise Stock Option | 70,000 | — | — | — | Sep 8, 2026 |
† change in this filer’s own reported holding line (Form 4 Table I, col. 5), not of total company ownership; small prior holdings produce large percentages, so under 100 shares the prior holding is shown instead.
“10b5-1 box checked” = the filer checked the Form 4 box stating that a transaction on the filing was made under a plan intended to satisfy Rule 10b5-1(c); “10b5-1 box not checked” = the box was left blank, which does not prove that no plan exists. The box applies to Form 4s filed from April 1, 2023; older filings, and boxes we could not read, carry no tag. What the 10b5-1 box means.
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Stock Option | 6,400 | — | — | — | Aug 12, 2026 |
| Grant / award Restricted Stock Units | 728 | — | — | — | Aug 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Restricted Stock Units | 728 | — | — | — | Aug 12, 2026 |
| Grant / award Stock Option | 6,400 | — | — | — | Aug 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Stock Option | 6,400 | — | — | — | Aug 12, 2026 |
| Grant / award Restricted Stock Units | 728 | — | — | — | Aug 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise Stock Option | 30,199 | — | — | — | Aug 20, 2026 |
| Open-market sale 10b5-1 box checked | 11,209 | $77.89 | 900 | −93% | Aug 20, 2026 |
| Option exercise | 30,199 | $19.49 | 31,099 | +3,355% | Aug 20, 2026 |
| Open-market sale 10b5-1 box checked | 30,365 | $77.45 | 12,109 | −71% | Aug 20, 2026 |
| Open-market sale 10b5-1 box checked | 13,625 | $76.34 | 42,474 | −24% | Aug 20, 2026 |
| Option exercise | 25,000 | $13.89 | 56,099 | +80% | Aug 20, 2026 |
| Option exercise Stock Option | 25,000 | — | — | — | Aug 20, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,200 | $80.29 | 3,800 | −24% | Aug 18, 2026 |
| Option exercise | 5,000 | $5.60 | 5,000 | — | Aug 18, 2026 |
| Open-market sale 10b5-1 box checked | 3,400 | $81.31 | 400 | −89% | Aug 18, 2026 |
| Open-market sale 10b5-1 box checked | 400 | $82.17 | 0 | −100% | Aug 18, 2026 |
| Option exercise Stock Option | 5,000 | — | — | — | Aug 18, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Restricted Stock Units | 6,208 | — | — | — | May 13, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 968 | $82.61 | 102,049 | −0.9% | Jun 5, 2026 |
| Open-market sale 10b5-1 box checked | 400 | $84.01 | 101,649 | −0.4% | Jun 5, 2026 |
| Open-market sale 10b5-1 box checked | 1,647 | $85.41 | 100,002 | −1.6% | Jun 5, 2026 |
| Option exercise Stock Option | 5,399 | — | — | — | Jun 5, 2026 |
| Open-market sale 10b5-1 box checked | 2,384 | $81.73 | 103,017 | −2.3% | Jun 5, 2026 |
| Option exercise | 5,399 | $13.89 | 105,401 | +5.4% | Jun 5, 2026 |
| Option exercise Stock Option | 13,351 | — | — | — | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 2,839 | $85.77 | 100,002 | −2.8% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 9,212 | $85.11 | 102,841 | −8.2% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 1,300 | $84.08 | 112,053 | −1.1% | Jun 4, 2026 |
| Option exercise | 13,351 | $13.89 | 113,353 | +13% | Jun 4, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise | 40,002 | $1.00 | 842,710 | +5.0% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 2,060 | $83.86 | 840,650 | −0.2% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 17,543 | $85.11 | 823,107 | −2.1% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 10,992 | $86.07 | 812,115 | −1.3% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 8,581 | $87.13 | 803,534 | −1.1% | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 826 | $87.91 | 802,708 | −0.1% | Jun 4, 2026 |
| Option exercise Stock Option | 40,002 | — | — | — | Jun 4, 2026 |
| Open-market sale 10b5-1 box checked | 4,300 | $87.57 | 858,408 | −0.5% | Jun 3, 2026 |
| Open-market sale 10b5-1 box checked | 1,187 | $93.04 | 802,708 | −0.1% | Jun 3, 2026 |
| Open-market sale 10b5-1 box checked | 5,843 | $92.38 | 803,895 | −0.7% | Jun 3, 2026 |
| Option exercise Stock Option | 60,000 | — | — | — | Jun 3, 2026 |
| Open-market sale 10b5-1 box checked | 9,925 | $90.78 | 809,738 | −1.2% | Jun 3, 2026 |
| Option exercise | 60,000 | $1.00 | 862,708 | +7.5% | Jun 3, 2026 |
| Open-market sale 10b5-1 box checked | 32,450 | $89.84 | 819,663 | −3.8% | Jun 3, 2026 |
| Open-market sale 10b5-1 box checked | 6,295 | $88.98 | 852,113 | −0.7% | Jun 3, 2026 |
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to ACMR's (Sep 10, 2026).
Frequently asked about ACMR insider activity
How many insiders bought ACMR stock in these Form 4 filings?
No open-market purchases (Form 4 code P) of ACMR shares were reported by Acm Research Inc insiders between Jun 5, 2026 and Sep 10, 2026. The 9 filings shown on this page cover other transaction types — sales, grants, option exercises, and tax withholding.
Who filed the most recent Form 4 for ACMR?
The most recent Form 4 on this page was filed by David H. Wang (Officer (see filing)) on Sep 10, 2026, reporting 13 transactions. The original document is linked from the filing list above on SEC EDGAR. Amended filings (Form 4/A) may later revise reported figures.
What was the largest open-market ACMR insider sale shown?
The largest open-market sale among the filings shown was 51,374 ACMR shares at $77.15 (about $3,963,504) by David H. Wang (Officer (see filing)) on Sep 8, 2026. Value is shares × the price reported on the Form 4; that Form 4 has the Rule 10b5-1 box checked.
New to Form 4s? The transaction codes, the 90-day window and the 0–100 score are defined on the insider-activity score methodology page.
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Track ACMR insider filings free →This score summarizes SEC Form 4 filing activity over the trailing 90 days. It is descriptive, not predictive — not a rating, recommendation, or investment advice. Data: SEC EDGAR (public domain), as filed; amendments may revise figures. Tradune is not a registered investment adviser.
Data as filed; amended filings (Form 4/A) may revise figures. Sales may occur under prearranged Rule 10b5-1 trading plans.