Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 133,072	$ 157,954
Investments	126,192	14,663
Prepaid expenses and other current assets	4,898	3,502
Total current assets	264,162	176,119
Property and equipment, net	7,783	5,771
Long-term investments	205	10,799
Deposits and other	3,043	3,026
Total assets	275,193	195,715
Current Liabilities
Accounts payable	2,524	2,133
Accrued expenses	5,309	5,395
Other current liabilities	1,442	419
Total current liabilities	9,275	7,947
Capital lease obligations, net of current portion	17	53
Deferred rent	4,621	763
Total liabilities	13,913	8,763
Commitments and contingencies (Note 8)
Stockholders’ equity
Additional paid-in capital	488,593	351,039
Accumulated other comprehensive income	117	16
Accumulated deficit	(227,434)	(164,106)
Total stockholders’ equity	261,280	186,952
Total liabilities and stockholders’ equity	275,193	195,715
Class A common stock
Stockholders’ equity
Common stock	3	2
Class B common stock
Stockholders’ equity
Common stock	$ 1	$ 1