Annual report pursuant to Section 13 and 15(d)

Statements of Stockholders' Equity

v3.20.1
Statements of Stockholders' Equity - USD ($)
shares in Thousands, $ in Thousands
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Accumulated Other Comprehensive Loss [Member]
Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2016 $ 21,789 $ 3 $ 172,425 $ (6) $ (150,633)
Beginning balance, shares at Dec. 31, 2016   26,119      
Issuance of common stock upon exercise of stock options $ 104 $ 0 104 0 0
Issuance of common stock upon exercise of stock options, shares 79 79      
Issuance of common stock for employee stock purchase plan $ 65 $ 0 65 0 0
Issuance of common stock for employee stock purchase plan, shares   24      
Share-based compensation 4,098 $ 0 4,076 0 22
Issuance of common stock, net of offering costs 30,610 $ 0 30,610 0 0
Issuance of common stock, net of offering costs, shares   5,980      
Repurchase of common stock (11,203) $ 0 (11,203) 0 0
Repurchase of common stock, shares   (2,167)      
Net loss (17,396) $ 0 0 0 (17,396)
Unrealized gain (loss) on marketable securities (71) 0 0 (71) 0
Ending balance at Dec. 31, 2017 27,996 $ 3 196,077 (77) (168,007)
Ending balance, shares at Dec. 31, 2017   30,035      
Issuance of common stock upon exercise of stock options $ 362 $ 0 362 0 0
Issuance of common stock upon exercise of stock options, shares 211 211      
Issuance of common stock for employee stock purchase plan $ 117 $ 0 117 0 0
Issuance of common stock for employee stock purchase plan, shares   36      
Share-based compensation 3,757 $ 0 3,757 0 0
Conversion of convertible note payable to common stock 13,729 $ 0 13,729 0 0
Conversion of convertible note payable to common stock, shares   2,883      
Cumulative effect of adoption of accounting standard (612) $ 0 0 0 (612)
Net loss (18,010) 0 0 0 (18,010)
Unrealized gain (loss) on marketable securities 60 0 0 60 0
Ending balance at Dec. 31, 2018 $ 27,399 $ 3 214,042 (17) (186,629)
Ending balance, shares at Dec. 31, 2018   33,165      
Issuance of common stock upon exercise of stock options, shares 0        
Issuance of common stock for employee stock purchase plan $ 3 $ 0 3 0 0
Issuance of common stock for employee stock purchase plan, shares   5      
Share-based compensation 4,153 $ 0 4,153 0 0
Net loss (11,385) 0 0 0 (11,385)
Unrealized gain (loss) on marketable securities 17 0 0 17 0
Ending balance at Dec. 31, 2019 $ 20,187 $ 3 $ 218,198 $ 0 $ (198,014)
Ending balance, shares at Dec. 31, 2019   33,170