Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 248,702	$ 202,818
Short-term investments	92,075	0
Accounts receivable, net	33,278	2,715
Inventory	14,673	10,112
Prepaid expenses and other current assets	7,940	4,530
Total current assets	396,668	220,175
Long-term investments	5,020	0
Property, plant and equipment, net	58,277	60,525
Operating lease right-of-use assets	17,216	0
Other assets	2,027	4,344
Total assets	479,208	285,044
Current liabilities
Accounts payable	11,480	12,403
Accrued expenses and other current liabilities	55,728	38,381
Operating lease liabilities	5,802	0
Total current liabilities	73,010	50,784
Convertible notes, net	183,553	0
Long-term operating lease liabilities	12,235	0
Other non-current liabilities	1,206	6,454
Total liabilities	270,004	57,238
Commitments and contingencies (Note 13)
Stockholders’ equity
Preferred stock, $0.001 par value; 15,000,000 shares authorized as of September 30, 2019 and December 31, 2018; None issued and outstanding	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized as of September 30, 2019 and December 31, 2018; 45,998,956 and 45,478,883 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	46	45
Additional paid-in capital	1,050,252	924,180
Accumulated other comprehensive loss	(158)	0
Accumulated deficit	(840,936)	(696,419)
Total stockholders’ equity	209,204	227,806
Total liabilities and stockholders’ equity	$ 479,208	$ 285,044