Stockholders' Equity (Tables)

9 Months Ended

Oct. 31, 2021

Share-based Payment Arrangement [Abstract]

A summary of stock option activity for the nine months ended October 31, 2021 is as follows:


	Number of shares	Weighted average exercise price		Weighted average remaining contractual term (in years)	Aggregate intrinsic value (in millions)
Options outstanding at January 31, 2021	12,761,289	$	57.48	5.0	$	2,794
Options granted	1,081,518	278.07
Options exercised	(1,074,939)	40.29
Options forfeited/cancelled	(267,795)	166.28
Options outstanding at October 31, 2021	12,500,073	$	75.71	4.8	$	3,016
Options vested and exercisable at October 31, 2021	7,197,020	$	28.82	2.8	$	2,074
Options vested and exercisable at October 31, 2021 and expected to vest thereafter	12,500,073	$	75.71	4.8	$	3,016

Schedule of Weighted-Average Assumptions Used to Estimate Grant Date Fair Value of Options Granted

The following table presents the weighted-average assumptions used to estimate the grant date fair value of options granted during the periods presented:


	Three months ended October 31,										Nine months ended October 31,
	2021					2020					2021					2020
Volatility	37%					39%		-	40%		37%		-	39%		39%		-	41%
Expected term (in years)	6.25					6.25					6.25					6.25		-	7.25
Risk-free interest rate	0.90	%	-	1.30	%	0.33	%	-	0.45	%	0.68	%	-	1.30	%	0.33	%	-	1.43	%
Dividend yield	—%					—%					—%					—%

Summary of Restricted Stock Unit (RSU) Activity

A summary of restricted stock unit (RSU) activity for the nine months ended October 31, 2021 is as follows:


	Unreleased restricted stock units	Weighted average grant date fair value
Balance at January 31, 2021	1,032,215	$	121.98
RSUs granted	442,514	280.61
RSUs vested	(663,283)	164.02
RSUs forfeited/cancelled	(57,443)	177.20
Balance at October 31, 2021	754,003	173.86