STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2026

Share-Based Payment Arrangement [Abstract]

Assumptions Used to Determine Fair Value of Options Granted

The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation with following assumptions:

	Six Months Ended June 30, 2026	Six Months Ended June 30, 2025
Fair value of share of common stock (1)	$48.31-$64.75	$24.33-$29.18
Expected term in years (2)	6.25	5.50-6.25
Volatility (3)	84.24%-84.46%	83.14%-83.28%
Risk-free interest rate (4)	3.92%-4.28%	4.18%-4.25%
Expected dividend (5)	—%	—%

(1)Fair value of Class A common stock value was closing market price of the Class A common stock on the grant date.

(2)Expected term of share options is based on the average of the vesting period and the contractual term for each grant.

(3)Volatility is calculated based on the historical volatility of ACM in the period equal to the expected term of each grant.

(4)Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant.

(5) Expected dividend is assumed to be nil as ACM has no history or expectation of paying a dividend on its Class A common stock.

Summary of Components of Stock-based Compensation Expense

The following table summarizes the components of stock-based compensation expense included in the condensed consolidated statements of comprehensive income:

	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Stock-based compensation expense:
Cost of revenue	$	177	$	356	$	525	$	885
Sales and marketing expense	1,330		2,096		2,822		4,253
Research and development expense	1,532		2,580		3,374		5,355
General and administrative expense	3,544		4,738		5,483		9,094
Total stock-based compensation expense	$	6,583	$	9,770	$	12,204	$	19,587