Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 143,940	$ 202,818
Short-term investments	165,250	0
Accounts receivable, net	38,354	2,715
Inventory	21,054	10,112
Prepaid expenses and other current assets	7,744	4,530
Total current assets	376,342	220,175
Property, plant and equipment, net	58,147	60,525
Operating lease right-of-use assets	16,523
Other assets	1,596	4,344
Total assets	452,608	285,044
Current liabilities
Accounts payable	12,770	12,403
Accrued expenses and other current liabilities	65,376	38,381
Operating lease liabilities	5,502
Total current liabilities	83,648	50,784
Convertible notes, net	188,651	0
Long-term operating lease liabilities	12,102
Other non-current liabilities	1,257	6,454
Total liabilities	285,658	57,238
Commitments and contingencies (Note 14)
Stockholders’ equity
Preferred stock, $0.001 par value; 15,000,000 shares authorized as of December 31, 2019 and December 31, 2018; None issued and outstanding	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized as of December 31, 2019 and December 31, 2018; 46,464,669 and 45,478,883 shares issued and outstanding as of December 31, 2019 and December 31, 2018, respectively	46	45
Additional paid-in capital	1,062,996	924,180
Accumulated other comprehensive loss	(92)	0
Accumulated deficit	(896,000)	(696,419)
Total stockholders’ equity	166,950	227,806
Total liabilities and stockholders’ equity	$ 452,608	$ 285,044