Consolidated Statements of Cash Flow - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2021	Aug. 01, 2020	Aug. 03, 2019
Cash Flows from Operating Activities
Net income (loss)	$ (8,876)	$ (67,117)	$ 36,881
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income taxes and valuation allowance	64	22,880	(8,203)
Inventory reserves	8,875	8,828	7,974
Stock-based compensation expense	100,696	67,530	35,256
Depreciation, amortization, and accretion	29,929	22,617	14,331
Other	(3,632)	882	148
Change in operating assets and liabilities:
Inventory	(96,056)	(15,222)	(41,233)
Prepaid expenses and other assets	(20,096)	(140)	(15,783)
Income tax receivables	(31,700)	(6,543)	(1,048)
Operating lease right-of-use assets and liabilities	(1,818)	394	0
Accounts payable	(12,385)	(5,520)	10,774
Accrued liabilities	22,011	8,297	22,856
Deferred revenue	5,082	1,054	3,325
Gift card liability	1,313	1,357	825
Other liabilities	(9,082)	3,580	12,491
Net cash provided by (used in) operating activities	(15,675)	42,877	78,594
Cash Flows from Investing Activities
Purchases of property and equipment	(35,256)	(30,207)	(30,825)
Purchases of securities available-for-sale	(173,726)	(248,318)	(285,205)
Sales of securities available-for-sale	104,501	36,587	10,596
Maturities of securities available-for-sale	143,574	171,477	80,250
Net cash provided by (used in) investing activities	39,093	(70,461)	(225,184)
Cash Flows from Financing Activities
Proceeds from the exercise of stock options, net	25,932	12,078	13,693
Payments for tax withholding related to vesting of restricted stock units	(64,316)	(12,819)	(6,748)
Issuance costs on revolving credit facility	(501)	(694)	0
Net cash provided by (used in) financing activities	(38,885)	(1,435)	6,945
Net increase (decrease) in cash and cash equivalents	(15,467)	(29,019)	(139,645)
Effect of exchange rate changes on cash	1,797	1,542	211
Cash and cash equivalents at beginning of period	143,455	170,932	310,366
Cash and cash equivalents at end of period	129,785	143,455	170,932
Supplemental Disclosure
Cash paid for income taxes	461	365	966
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Purchases of property and equipment included in accounts payable and accrued liabilities	3,803	4,088	5,272
Capitalized stock-based compensation	5,693	2,450	1,789
Leasehold improvements paid by landlord		7,406	0
Vesting of early exercised options	$ 0	$ 0	$ 209