Stock-Based Compensation

9 Months Ended

Sep. 28, 2024

Share-Based Payment Arrangement [Abstract]

Stock-based compensation costs are based on the fair values on the date of grant for stock awards and stock options and on the date of enrollment for the employee stock purchase plans. The fair values of stock awards (such as restricted stock units (“RSUs”), performance stock units (“PSUs”) and restricted stock awards (“RSAs”)) are estimated based on their intrinsic values. The fair values of market stock awards (“MSUs”) are estimated using a Monte Carlo simulation. The fair values of stock options and employee stock purchase plans are estimated using the Black-Scholes option-pricing model.

The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Operations (in thousands):


	Three Months Ended				Nine Months Ended
	September 28, 2024		September 30, 2023		September 28, 2024		September 30, 2023
Cost of revenues	$	369	$	192	$	1,193	$	774
Research and development	10,255		8,598		30,194		26,903
Selling, general and administrative	5,279		(3,000)		13,971		9,490
	15,903		5,790		45,358		37,167
Income tax benefit	2,252		505		6,054		4,446
Total	$	13,651	$	5,285	$	39,304	$	32,721

For the three months ended September 30, 2023, the Company recognized an expense reversal of $9.5 million to reflect a reduction in the estimated levels of achievement related to unvested performance stock units.

The Company had approximately $110.0 million of total unrecognized compensation cost related to equity grants as of September 28, 2024 that is expected to be recognized over a weighted-average period of approximately 2.2 years.