CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 111,959	$ 138,976
Available-for-sale securities	939,338	497,972
Accounts receivable, net	48,783	33,867
Contract assets	2,086	2,063
Restricted cash short-term	2,187	0
Prepaid expenses and other current assets	23,026	16,994
Total current assets	1,127,379	689,872
Property and equipment, net	122,423	101,466
Goodwill	17,167	4,083
Acquired intangible assets, net	3,500	31
Operating lease right-of-use assets	45,106	0
Deferred contract acquisition costs, noncurrent	37,714	25,184
Restricted cash	6,660	6,660
Other noncurrent assets	11,276	3,528
Total assets	1,371,225	830,824
Current liabilities:
Accounts payable	16,995	11,463
Accrued expenses and other current liabilities	38,630	28,314
Operating lease liabilities	17,265	0
Liability for early exercise of unvested stock options	9,679	13,263
Deferred revenue	48,435	30,843
Total current liabilities	131,004	83,883
Convertible senior notes, net	374,511	0
Build-to-suit lease financing obligation	0	10,506
Operating lease liabilities, noncurrent	29,675	0
Deferred revenue, noncurrent	1,637	804
Other noncurrent liabilities	7,951	9,803
Total liabilities	544,778	104,996
Commitments and contingencies (Note 8)
Stockholders’ Equity:
Additional paid-in capital	1,212,074	1,027,179
Accumulated deficit	(386,499)	(301,706)
Accumulated other comprehensive income	570	61
Total stockholders’ equity	826,447	725,828
Total liabilities and stockholders’ equity	1,371,225	830,824
Class A common stock
Stockholders’ Equity:
Common stock	233	87
Class B common stock
Stockholders’ Equity:
Common stock	$ 69	$ 207