Quarterly report pursuant to Section 13 or 15(d)

Condensed Statement of Changes in Stockholders' Equity

v3.20.2
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, 2018 18,370,435 $ 265 243,111,741 (224,741,571)
Beginning balance (in shares) at Dec. 31, 2018   26,526,303    
Net loss (29,007,691)      
Ending balance at Sep. 30, 2019 21,278,035 $ 309 275,026,988 (253,749,262)
Ending balance (in shares) at Sep. 30, 2019   30,844,921    
Beginning balance at Mar. 31, 2019 34,075,419 $ 303 269,836,155 (235,761,039)
Beginning balance (in shares) at Mar. 31, 2019   30,328,549    
Stock-based compensation - restricted stock units ("RSUs") 2,675,184   2,675,184  
Stock-based compensation - employee stock purchase plan ("ESPP") 122,749   122,749  
Issuance of shares for RSUs   $ 2 (2)  
Issuance of shares for RSUs (in shares)   189,220    
Proceeds from contributions to the ESPP 145,422   145,421  
Proceeds from contributions to the ESPP (in shares)   85,765    
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs   $ 1    
Net loss (9,803,996)     (9,803,996)
Ending balance at Jun. 30, 2019 27,214,778 $ 306 272,779,507 (245,565,035)
Ending balance (in shares) at Jun. 30, 2019   30,603,534    
Stock-based compensation - restricted stock units ("RSUs") 2,037,620   2,037,620  
Stock-based compensation - employee stock purchase plan ("ESPP") 62,055   62,055  
Issuance of shares for RSUs   $ 3 (3)  
Issuance of shares for RSUs (in shares)   280,053    
Shares returned (in shares)   (38,666)    
Proceeds from contributions to the ESPP 147,809   147,809  
Net loss (8,184,227)     (8,184,227)
Ending balance at Sep. 30, 2019 21,278,035 $ 309 275,026,988 (253,749,262)
Ending balance (in shares) at Sep. 30, 2019   30,844,921    
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs 4,557,693      
Ending balance at Dec. 31, 2019 19,012,874 $ 333 282,153,201 (263,140,660)
Ending 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    
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    
Net loss (24,359,239)      
Ending balance at Sep. 30, 2020 19,042,028 $ 431 306,541,496 (287,499,899)
Ending balance (in shares) at Sep. 30, 2020   43,062,944    
Beginning balance at Mar. 31, 2020 18,311,376 $ 381 290,049,391 (271,738,396)
Beginning balance (in shares) at Mar. 31, 2020   37,952,017    
Stock-based compensation - restricted stock units ("RSUs") 2,028,599   2,028,599  
Stock-based compensation - employee stock purchase plan ("ESPP") 41,308   41,308  
Issuance of shares for RSUs   $ 2 (2)  
Issuance of shares for RSUs (in shares)   232,995    
Proceeds from contributions to the ESPP 104,145 $ 1 104,144  
Proceeds from contributions to the ESPP (in shares)   144,370    
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs 9,216,611 $ 33 9,216,578  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs (in shares)   3,355,928    
Net loss (8,204,666)     (8,204,666)
Ending balance at Jun. 30, 2020 21,497,373 $ 417 301,440,018 (279,943,062)
Ending balance (in shares) at Jun. 30, 2020   41,685,310    
Stock-based compensation - restricted stock units ("RSUs") 1,876,686   1,876,686  
Stock-based compensation - employee stock purchase plan ("ESPP") 96,056   96,056  
Issuance of shares for RSUs   $ 4 (4)  
Issuance of shares for RSUs (in shares)   361,608    
Proceeds from contributions to the ESPP 121,692   121,692  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs 3,007,058 $ 10 3,007,048  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs (in shares)   1,016,026    
Net loss (7,556,837)     (7,556,837)
Ending balance at Sep. 30, 2020 $ 19,042,028 $ 431 $ 306,541,496 $ (287,499,899)
Ending balance (in shares) at Sep. 30, 2020   43,062,944