EQUITY AWARD PLANS (Tables)

12 Months Ended

Jul. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

summary of RSU activity under the Stock Plans:



	Fiscal Year Ended July 31,
	2017				2018
	Number of Shares		Grant Date Fair Value per Share		Number of Shares		Grant Date Fair Value per Share
Outstanding at beginning of period	12,265,369		$	13.23	17,376,090		$	18.85
Granted	12,986,597		$	21.84	14,947,403		$	39.44
Released	(6,146,169	)	$	15.63	(5,823,800	)	$	19.96
Canceled/forfeited	(1,729,707	)	$	13.57	(2,902,194	)	$	22.34
Outstanding at end of period	17,376,090		$	18.85	23,597,499		$	31.20

Schedule of Employee Stock Purchase Plan, Valuation Assumptions

We use the Black-Scholes option pricing model to determine the fair value of shares purchased under the 2016 ESPP with the following weighted average assumptions on the date of grant:



	Fiscal Year Ended July 31,
	2017		2018
Expected term (in years)	0.75		0.75
Risk-free interest rate	0.6	%	1.4	%
Volatility	51.0	%	49.8	%
Dividend yield	—	%	—	%

Schedule of Stock Option Activity

The stock option activity under the Stock Plans is as follows:



	Fiscal Year Ended July 31,
	2017								2018
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value		Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value
						(in years)	(in thousands)						(in years)	(in thousands)
Outstanding at beginning of period	26,166,968		⁽¹⁾	$	4.39	7.5	$	208,101	20,334,531		$	4.59	6.4	$	338,787
Options granted	1,047,950			$	12.14				—		$	—
Options exercised	(4,786,381	)		$	3.27				(8,672,623	)	$	3.81
Options canceled/forfeited	(2,094,006	)		$	8.89				(329,354	)	$	6.63
Outstanding at end of period	20,334,531			$	4.59	6.4	$	338,787	11,332,554		$	5.12	5.6	$	496,022
Exercisable at end of period	19,645,676			$	4.43	6.3	$	330,486	11,159,045		$	5.01	5.5	$	489,682
Vested and expected to vest at end of period	20,334,531			$	4.59	6.4	$	338,787	11,332,554		$	5.12	5.6	$	496,022

(1)

Includes 455,000 stock options with both service and performance conditions with a weighted average fair value per share of $3.78 (the "Performance Stock Options"). Vesting of the Performance Stock Options was subject to continuous service with us (the "service condition") and satisfaction of certain liquidity events (the "performance condition"). We recognized cumulative stock-based compensation expense related to the Performance Stock Options in the first quarter of fiscal 2017, as the performance condition was met upon the successful completion of our IPO. The cumulative stock-based compensation expense recorded in the first quarter of fiscal 2017 was for the portion of the awards for which the relevant service condition had been satisfied and the remaining expense is being recognized over the remaining service period.

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

Stock-Based Compensation

Total stock-based compensation expense recognized in the consolidated statements of operations is as follows:



	Fiscal Year Ended July 31,
	2016		2017		2018
	(in thousands)
Cost of revenue:
Product	$	391	$	3,066	$	2,580
Support, entitlements and other services	968		10,411		8,945
Sales and marketing	8,006		78,117		65,060
Research and development	6,259		109,044		74,389
General and administrative	4,432		30,853		26,894
Total stock-based compensation expense	$	20,056	$	231,491	$	177,868

Schedule Stock Option Valuation Assumptions

The fair value of our stock options was estimated using the following weighted average assumptions:



	Fiscal Year Ended July 31,
	2016			2017
Fair value of common stock	$	14.81		$	12.14
Expected term (in years)	6.1			6.1
Risk-free interest rate	1.6		%	1.3		%
Volatility	42		%	52		%
Dividend yield	—		%	—		%