ACM Research ACMR Insider Ownership

NASDAQ ACMR

$76.17 -7.21 (-8.65%)

At close: Oct 5, 2026 · 4:00 PM EDT

Insider Holdings by Owner

6.09Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

5.53%

▼-0.068% pp QoQ

Shares Held by Insiders

3.76Mn

filed for Sep 2026

▼-1.21% QoQ

Shares Outstanding

67.89Mn

67,890,917 shares

Direct Holdings

1.42Mn

Indirect: 2.34Mn

Net Shares Traded (QoQ)

-45.84K

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 5, 2026

Over the past year, ACMR insiders sold $51.15 million of stock (948.75K shares) on the open market and bought none.

Behind ACM Research's open-market sales in the past 12 months were 8 insiders, and no insider bought.
David H. Wang (Director, officer and 10% owner) sold the most ACM Research stock on the open market over the past 12 months, $28.98 million (480K shares), most recently on September 9, 2026.
Apart from open-market trades, ACMR insiders acquired 948.75K shares through option exercises and conversions and gave away 755.09K shares as gifts in the past 12 months.
Per Business Quant, ACMR insiders together hold 3.76Mn shares based on their latest Form 4 filings, down 1.21% from 3.8Mn shares at the end of Q2 2026 and down 17.58% from 4.56Mn shares at the end of Q3 2025.
By type of ownership, ACMR insiders hold 37.74% of their shares directly (1.42Mn shares) and 62.26% indirectly (2.34Mn shares).
The insider holdings in ACM Research belong to 8 insiders who have reported on Form 4 within the past two years.
ACMR's three largest insider shareholders, per their latest Form 4 filings, are Xiao Xing (Director, 2.34Mn shares), David H. Wang (Director, officer and 10% owner, 802.71K shares) and Jian Wang (Officer, 253.16K shares).
The largest insider, Xiao Xing, holds 62.26% of ACMR's insider total.
Institutions owned 75.79% of ACMR shares as of Q2 2026; insiders' latest Form 4 filings account for about 5.53%, leaving roughly 18.68% with other investors, including the public.
Over the past 12 months, 8 insiders reported transactions in ACM Research stock in 24 Form 4 filings.
These insider figures for ACM Research are based on Form 4 filings through September 10, 2026.

Form 4 Holdings

Insiders Holding ACMR

Insiders 9

Shares held 6.09Mn

Of outstanding 8.98%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Science Technology Venture Capital (Group) Co., Ltd. Shanghai	TenPercentOwner, Other	2,338,510	0	2,338,510	38.4%	08 Oct, 2024
2	Xiao Xing	Director	0	2,338,510	2,338,510	38.4%	08 Oct, 2024
3	David H Wang	Director, Officer, TenPercentOwner	802,708	0	802,708	13.2%	10 Sep, 2026
4	Jian Wang	Officer	253,158	0	253,158	4.2%	19 Sep, 2025
5	Tracy Liu	Director	110,772	0	110,772	1.8%	12 Mar, 2026
6	Chenming Hu	Director	100,002	0	100,002	1.6%	19 Mar, 2025
7	Sotheara Cheav	Officer	100,002	0	100,002	1.6%	05 Jun, 2026
8	Lisa Feng	Officer	50,001	0	50,001	0.8%	09 Mar, 2026
9	Mark Mckechnie	Officer	900	0	900	0.0%	21 Aug, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

628 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Acquired M	70,000	$1.00	$70.00K	872,708	Direct
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	4,803	$75.99	$364.98K	867,905	Direct
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	51,374	$77.15	$3.96Mn	816,531	Direct
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	12,323	$78.08	$962.18K	804,208	Direct
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	1,500	$78.57	$117.85K	802,708	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Acquired M	70,000	$1.00	$70.00K	872,708	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	33,493	$73.80	$2.47Mn	839,215	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	18,934	$74.67	$1.41Mn	820,281	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	11,666	$75.58	$881.72K	808,615	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	4,807	$76.73	$368.84K	803,808	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed S	1,100	$77.59	$85.35K	802,708	Direct
08 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed M	70,000	$0.00	$0	200,000	Direct
09 Sep, 2026	David H Wang	Director, Officer, TenPercentOwner	Disposed M	70,000	$0.00	$0	130,000	Direct
12 Aug, 2026	Tracy Liu	Director	Acquired A	6,400	$0.00	$0	6,400	Direct
12 Aug, 2026	Haiping Dun	Director	Acquired A	6,400	$0.00	$0	6,400	Direct
12 Aug, 2026	Charles C Pappis	Director	Acquired A	6,400	$0.00	$0	6,400	Direct
12 Aug, 2026	Tracy Liu	Director	Acquired A	728	$0.00	$0	728	Direct
12 Aug, 2026	Haiping Dun	Director	Acquired A	728	$0.00	$0	728	Direct
12 Aug, 2026	Charles C Pappis	Director	Acquired A	728	$0.00	$0	728	Direct
20 Aug, 2026	Mark Mckechnie	Officer	Acquired M	30,199	$19.49	$588.58K	31,099	Direct

Showing 1 to 20 of 628 transactions