CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
CURRENT ASSETS
Cash and cash equivalents	$ 53,581	$ 10,435
Short-term investments	142,851	81,345
Accounts receivable, net of allowance for doubtful accounts of $263 and $238, respectively	13,611	11,720
Inventory	5,633	5,452
Prepaid expenses and other current assets	2,565	2,510
Total current assets	218,241	111,462
Long-term investments	0	1,278
Property and equipment, net	4,527	3,954
Other non-current assets	374	315
TOTAL ASSETS	223,142	117,009
CURRENT LIABILITIES
Accounts payable	3,271	2,811
Accrued liabilities and other	10,199	11,605
Current portion of long-term borrowings	0	4,358
Total current liabilities	13,470	18,774
Long-term borrowings	39,455	34,865
Other long-term liabilities	854	362
TOTAL LIABILITIES	53,779	54,001
Commitments and contingencies (Note 6)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized; 32,583,220 and 25,163,803 shares issued and outstanding, respectively	3	3
Additional paid-in capital	408,113	258,121
Accumulated other comprehensive income	524	464
Accumulated deficit	(239,277)	(195,580)
TOTAL STOCKHOLDERS’ EQUITY	169,363	63,008
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 223,142	$ 117,009