MCKECHNIE MARK (See Remarks) sold 98.4% of their position (55.20K shares) of ACM RESEARCH, INC. on the open market

Open‑market sale worth $4.26M — a major position exit. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 3 sales

MCKECHNIE MARK

Filed: 8/22/2026ACC: 0001140361-26-034070

InsiderMCKECHNIE MARKCIK 1775007

→

IssuerACM RESEARCH, INC.CIK 1680062

Officer· See Remarks

Since Jun 2019

-55.20K

Net shares

Net seller

$4.26M

Total sold

Open market trades

0B · 3S

Total transactions

55.20K acquired · 110.40K disposed

Non-Derivative Transactions5

Class A Common Stock

Direct

M · Option Exercise

+30.20K

Price / share

$19.49

Trade value

$588.58K

% of position

3355.4%

8/20/2026

900.00→31.10K

Class A Common Stock

Direct

M · Option Exercise

+25K

Price / share

$13.89

Trade value

$347.25K

% of position

80.4%

8/20/2026

31.10K→56.10K

Class A Common Stock

Direct

S · Sale

−13.63K

Price / share

$76.34

Trade value

$1.04M

% of position

24.3%

8/20/2026

56.10K→42.47K

Class A Common Stock

Direct

S · Sale

−30.36K

Price / share

$77.45

Trade value

$2.35M

% of position

71.5%

8/20/2026

42.47K→12.11K

Class A Common Stock

Direct

S · Sale

−11.21K

Price / share

$77.89

Trade value

$873.07K

% of position

92.6%

8/20/2026

12.11K→900.00

Total

Net shares

+0.00

Net value

-$3.33M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Class A Common Stock Direct	8/20/2026	M · Option Exercise	+30.20K	$19.49	$588.58K	3355.4%	900.00	31.10K
Class A Common Stock Direct	8/20/2026	M · Option Exercise	+25K	$13.89	$347.25K	80.4%	31.10K	56.10K
Class A Common Stock Direct	8/20/2026	S · Sale	−13.63K	$76.34	$1.04M	24.3%	56.10K	42.47K
Class A Common Stock Direct	8/20/2026	S · Sale	−30.36K	$77.45	$2.35M	71.5%	42.47K	12.11K
Class A Common Stock Direct	8/20/2026	S · Sale	−11.21K	$77.89	$873.07K	92.6%	12.11K	900.00
Total			+0.00		-$3.33M

Derivative Transactions2

Stock Option

Direct

M · Option Exercise

Converts to

Class A Common Stock

30.20K shares

−30.20K

Strike price

19.49

Held after

31.25K

Exercisable

—

8/20/2026

Stock Option

Direct

M · Option Exercise

Converts to

Class A Common Stock

25K shares

−25K

Strike price

13.89

Held after

215K

Exercisable

—

8/20/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Stock Option Direct	Class A Common Stock30.20K shares	8/20/2026	M · Option Exercise	−30.20K	19.49	—	31.25K
Stock Option Direct	Class A Common Stock25K shares	8/20/2026	M · Option Exercise	−25K	13.89	—	215K