Stock Based Compensation (Tables)

3 Months Ended

Oct. 28, 2017

Summary of Stock Option Activity Under 2011 Stock Plan

Stock option activity under the 2011 Plan is as follows:

				Options Outstanding
	Shares Available for Grant			Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in Years)		Aggregate Intrinsic Value
											(In thousands)
Balance – July 29, 2017		2,023,424			10,218,912		$	7.12		8.53	$	166,670
Repurchased		19,479
Granted		(867,865	)		867,865		$	23.43
Exercised		—			(211,236	)	$	2.10
Cancelled		551,641			(551,641	)	$	4.01
Balance – October 28, 2017		1,726,679			10,323,900		$	8.76		8.45	$	87,531

Summary of Assumptions Used in Black-Scholes Option-Pricing Model to Determine Fair Value of Stock Options

The fair value of stock options granted to employees was estimated at the grant date using the Black- Scholes option-pricing model with the following assumptions:

	Three Months Ended
	October 28, 2017	October 29, 2016
Expected term (in years)	5.6 – 6.5	5.4 – 6.5
Volatility	42.1 – 43.5%	44.4 – 46.0%
Risk free interest rate	1.9 – 2.0%	1.3 – 1.5%
Dividend yield	— %	— %