CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 36,594	$ 34,986
Short-term investments	97,000	50,732
Accounts receivable	21,166	16,882
Inventories, net	23,254	19,490
Prepaid and other current assets	5,417	6,018
Total current assets	183,431	128,108
Non-current assets:
Property and equipment, net	13,867	14,898
Goodwill	1,316	1,316
Operating lease right-of-use assets	13,122	14,122
Intangible assets, net		132
Restricted cash	2,309	2,435
Other assets	7,370	4,524
Total assets	221,415	165,535
Current liabilities:
Accounts payable	24,213	22,185
Accrued liabilities	24,753	20,951
Debt – current	8,516	5,017
Operating lease liabilities – current	1,915	1,613
Deferred product revenue	577	570
Total current liabilities	59,974	50,336
Non-current liabilities:
Debt – non-current	39,588	39,414
Operating lease liabilities – non-current	16,873	18,406
Other non-current liabilities	1,174	327
Total liabilities	117,609	108,483
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares authorized, issuable in series; zero shares issued and outstanding at December 31, 2020 and 2019, respectively
Common stock, $0.001 par value; 225,000 shares authorized; 168,170 and 144,291 shares issued and outstanding at December 31, 2020 and 2019, respectively	168	144
Additional paid-in capital	1,012,932	906,905
Accumulated other comprehensive income	674	114
Accumulated deficit	(909,968)	(850,111)
Total stockholders' equity	103,806	57,052
Total liabilities and stockholders' equity	$ 221,415	$ 165,535