CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 89,482	$ 37,878
Short term investments	47,822	34,751
Accounts receivable	5,338	15,546
Prepaid expenses and other current assets	4,207	1,615
Total current assets	146,849	89,790
Property and equipment, net	4,687	4,034
Long term investments	0	9,922
Other non-current assets	121	130
Total assets	151,657	103,876
Current liabilities:
Accounts payable	2,693	2,452
Accrued expenses and other current liabilities	5,981	6,170
Deferred revenues, current portion	31,920	37,153
Total current liabilities	40,594	45,775
Deferred revenue, net of current portion	60,770	46,542
Other long-term liabilities	32	37
Total liabilities	101,396	92,354
Stockholders’ equity:
Preferred stock, $0.001 par value per share, 10,000,000 shares authorized and 2,907 and 4,963 issued and outstanding at September 30, 2018 and December 31, 2017, respectively	0	0
Common stock, $0.001 par value per share, 300,000,000 shares authorized and 54,149,719 and 45,017,062 issued and outstanding at September 30, 2018 and December 31, 2017, respectively	54	45
Additional paid-in capital	188,644	136,484
Accumulated other comprehensive loss	(3,053)	(4,695)
Accumulated deficit	(135,384)	(120,312)
Total stockholders’ equity	50,261	11,522
Total liabilities and stockholders’ equity	$ 151,657	$ 103,876