Stock-based Compensation

3 Months Ended

Apr. 30, 2023

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

10. Stock-based Compensation

The following table presents the classification of stock-based compensation for the periods indicated:


	Three Months Ended April 30,
	2023		2022
	(in thousands)
Stock-based compensation:
Cost of revenue	$	941	$	349
Research and development		18,361		17,151
Selling, general and administrative		7,963		9,541
Total stock-based compensation	$	27,265	$	27,041

As of April 30, 2023, approximately $1.0 million of stock-based compensation expense was accrued in accrued and other current liabilities in the condensed consolidated balance sheets. Total unrecognized compensation cost related to unvested stock options at April 30, 2023 was $13.3 million and is expected to be recognized over a weighted-average period of 1.70 years. Total unrecognized compensation cost related to unvested restricted stock units at April 30, 2023 was $201.5 million and is expected to be recognized over a weighted-average period of 2.46 years.

The following table sets forth the weighted-average assumptions used to estimate the fair value of employee stock purchase plan awards for the periods indicated:


	Three Months Ended April 30,
	2023			2022
Employee stock purchase plan awards:
Volatility		59	%		89	%
Risk-free interest rate		4.73	%		0.86	%
Expected term (years)	0.5			0.5
Dividend yield		0	%		0	%

The following table summarizes stock option activities for the period indicated:


	Option Outstanding
									Weighted-
							Total Intrinsic		Average
						Weighted-	Value Of		Remaining		Aggregate
				Weighted-		Average	Options		Contractual		Intrinsic
				Average		Grant-date	Exercised		Term		Value
	Shares			Exercise Price		Fair Value	(in thousands)		(in years)		(in thousands)
Outstanding at January 31, 2023		484,791		$	42.18
Exercised		(28,334	)		23.02		$	1,758
Forfeited		(648	)		41.49
Outstanding at April 30, 2023		455,809			43.37					4.20	$	17,106
Exercisable at April 30, 2023		361,063		$	45.54					3.50	$	12,700

The intrinsic value of options outstanding and exercisable is calculated based on the difference between the fair market value of the Company’s ordinary shares on the reporting date and the exercise price. The closing price of the Company’s ordinary shares on April 28, 2023 was $61.98, as reported by The NASDAQ Global Market. The intrinsic value of exercised options is calculated based on the difference between the fair market value of the Company’s ordinary shares on the exercise date and the exercise price.

The following table summarizes restricted stock unit activities for the period indicated:


				Weighted-
				Average
				Grant-Date
	Shares			Fair Value
Unvested at January 31, 2023		2,573,359		$	86.81
Granted		419,517			88.91
Vested		(439,662	)		75.89
Forfeited		(63,023	)		67.28
Unvested at April 30, 2023		2,490,191		$	89.59

As of April 30, 2023, the aggregate intrinsic value of unvested restricted stock units was $154.3 million.