The Company uses the Black-Scholes option pricing model to calculate the fair value of stock option awards, whether they possess time-based vesting provisions or performance-based vesting provisions, and awards granted under the Vicor Corporation 2017 Employee Stock Purchase Plan (“ESPP”), as of their grant date. Stock-based compensation expense was as follows (in thousands):


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2026		2025		2026		2025
Cost of product revenues	$	897	$	899	$	1,733	$	1,866
Selling, general and administrative		2,085		1,790		4,044		3,984
Research and development		1,198		1,020		2,255		2,208
Total stock-based compensation	$	4,180	$	3,709	$	8,032	$	8,058

Compensation expense by type of award was as follows (in thousands):


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2026		2025		2026		2025
Stock options	$	3,792	$	3,386	$	7,319	$	7,463
ESPP		388		323		713		595
Total stock-based compensation	$	4,180	$	3,709	$	8,032	$	8,058