Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 75,497	$ 182,348
Short-term investments	186,565	157,140
Accounts receivable, net	24,627	25,600
Inventories	53,689	39,185
Prepaid expenses and other current assets	5,399	5,529
Total current assets	345,777	409,802
Restricted cash	33,311	33,311
Property and equipment, net	15,245	12,964
Operating lease right-of-use assets	6,687	7,231
Other assets	216	156
Total assets	401,236	463,464
Current liabilities:
Accounts payable	2,753	1,763
Accrued compensation and related benefits	15,795	24,948
Accrued expenses and other current liabilities	23,261	13,789
Accrued warranty liability	3,444	3,704
Deferred revenue, current	7,752	6,340
Operating lease liabilities, current	1,235	1,151
Term loan, current	1,000	0
Total current liabilities	55,240	51,695
Accrued interest, noncurrent	960	721
Deferred revenue, noncurrent	205	312
Operating lease liabilities, noncurrent	6,261	6,893
Term loan, noncurrent	28,806	29,762
Total liabilities	91,472	89,383
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares authorized, and no shares issued and outstanding as of June 30, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value; 300,000 shares authorized as of June 30, 2022 and December 31, 2021; 47,997 and 47,241 shares issued and outstanding as of June 30, 2022 and December 31, 2021, respectively	48	47
Additional paid-in capital	1,017,396	1,000,212
Accumulated other comprehensive (loss) income	(955)	(184)
Accumulated deficit	(706,725)	(625,994)
Total stockholders' equity	309,764	374,081
Total liabilities and stockholders' equity	$ 401,236	$ 463,464