Stock-based Compensation (Tables)

6 Months Ended

Jul. 31, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Classification of Stock-based Compensation

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

	Three Months Ended July 31,				Six Months Ended July 31,
	2022		2021		2022		2021
	(in thousands)
Stock-based compensation:
Cost of revenue	$	362	$	359	$	711	$	682
Research and development		17,883		11,525		35,034		22,719
Selling, general and administrative		8,664		7,488		18,205		14,813
Total stock-based compensation	$	26,909	$	19,372	$	53,950	$	38,214

Weighted-Average Assumptions Used to Estimate Fair Value

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

	Three Months Ended July 31,					Six Months Ended July 31,
	2022		2021			2022			2021
Stock Options:
Volatility		—		50	%		—			51	%
Risk-free interest rate		—		0.85	%		—			0.98	%
Expected term (years)		—	5.06				—		5.27
Dividend yield		—		0	%		—			0	%
Employee stock purchase plan awards:
Volatility		—		—			89	%		61	%
Risk-free interest rate		—		—			0.86	%		0.06	%
Expected term (years)		—		—		0.5			0.5
Dividend yield		—		—			0	%		0	%

Stock Option Activities

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, 2022		619,322		$	40.08
Granted		—			—		—
Exercised		(64,395	)		32.20			$	3,878
Forfeited		(6,323	)		45.88
Expired		(518	)		10.89
Outstanding at July 31, 2022		548,086			40.97					4.68		$	25,303
Exercisable at July 31, 2022		386,400		$	43.27						3.59	$	16,853

Restricted Stock Unit Activities

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

				Weighted-
				Average
				Grant-Date
	Shares			Fair Value
Unvested at January 31, 2022		2,651,135		$	85.41
Granted		708,985			85.87
Vested		(995,693	)		68.42
Forfeited		(61,722	)		100.28
Unvested at July 31, 2022		2,302,705		$	92.87