CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 66,169	$ 10,435
Short-term investments	71,499	81,345
Accounts receivable, net of allowance for doubtful accounts of $263 and $238, respectively	10,260	11,720
Inventory	4,969	5,452
Prepaid expenses and other current assets	1,632	2,510
Total current assets	154,529	111,462
Long-term investments	0	1,278
Property and equipment, net	4,407	3,954
Other non-current assets	312	315
TOTAL ASSETS	159,248	117,009
Current liabilities:
Accounts payable	2,455	2,811
Accrued liabilities and other	9,272	11,605
Current portion of long-term borrowings	0	4,358
Total current liabilities	11,727	18,774
Long-term borrowings	39,264	34,865
Other long-term liabilities	389	362
TOTAL LIABILITIES	51,380	54,001
Commitments and contingencies
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; 28,612,451 and 25,163,803 shares issued and outstanding, respectively	3	3
Additional paid-in capital	328,079	258,121
Accumulated other comprehensive income	610	464
Accumulated deficit	(220,824)	(195,580)
TOTAL STOCKHOLDERS’ EQUITY	107,868	63,008
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 159,248	$ 117,009