Quarterly report pursuant to Section 13 or 15(d)

Condensed Statement of Changes in Stockholders' Equity

v3.20.1
Condensed Statement of Changes in Stockholders' Equity - USD ($)
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2018 $ 18,370,435 $ 265 $ 243,111,741 $ (224,741,571)
Beginning balance (in shares) at Dec. 31, 2018   26,526,303    
Stock-based compensation - restricted stock units ("RSUs") 3,083,567   3,083,567  
Stock-based compensation - employee stock purchase plan ("ESPP") 87,825   87,825  
Issuance of shares for RSUs   $ 4 (4)  
Issuance of shares for RSUs (in shares)   434,522    
Shares withheld for payroll tax on RSUs (10,207)   (10,207)  
Shares withheld for payroll tax on RSUs (in shares)   (1,329)    
Shares withheld for payroll tax on performance share units ("PSUs") (329,159)   (329,159)  
Shares withheld for payroll tax on performance share units ("PSUs") (in shares)   (44,481)    
Exercise of stock options 400,103 $ 1 400,102  
Exercise of stock options (in shares)   80,201    
Proceeds from contributions to the ESPP 173,167   173,167  
Issuance of shares and warrants in a private placement, net of issuance costs 23,319,156 $ 33 23,319,123  
Issuance of shares and warrants in a private placements, net of issuance costs (in shares)   3,333,333    
Net loss (11,019,468)     (11,019,468)
Ending balance at Mar. 31, 2019 34,075,419 $ 303 269,836,155 (235,761,039)
Ending balance (in shares) at Mar. 31, 2019   30,328,549    
Beginning balance at Dec. 31, 2019 19,012,874 $ 333 282,153,201 (263,140,660)
Beginning balance (in shares) at Dec. 31, 2019   33,203,806    
Stock-based compensation - restricted stock units ("RSUs") 2,321,820   2,321,820  
Stock-based compensation - performance share units ("PSUs") (88,348)   (88,348)  
Stock-based compensation - employee stock purchase plan ("ESPP") 42,827   42,827  
Issuance of shares for RSUs   $ 4 (4)  
Issuance of shares for RSUs (in shares)   396,559    
Proceeds from contributions to the ESPP 113,059   113,059  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs 5,506,880 $ 44 5,506,836  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs (in shares)   4,351,652    
Net loss (8,597,736)     (8,597,736)
Ending balance at Mar. 31, 2020 $ 18,311,376 $ 381 $ 290,049,391 $ (271,738,396)
Ending balance (in shares) at Mar. 31, 2020   37,952,017