Annual report pursuant to Section 13 and 15(d)

Statement of Changes in Stockholder's Equity

v3.21.1
Statement of Changes in Stockholder's 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") 10,190,211   10,190,211  
Stock-based compensation - employee stock purchase plan ("ESPP") 368,021   368,021  
Stock-based compensation - performance share units ("PSUs") 88,348   88,348  
Issuance of shares for RSUs   $ 11 (11)  
Issuance of shares for RSUs (in shares)   1,110,817    
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 PSUs (329,159)   (329,159)  
Shares withheld for payroll tax on PSUs (in shares)   (44,481)    
Shares returned (in shares)   (38,666)    
Exercise of stock options 400,103 $ 1 400,102  
Exercise of stock options (in shares)   80,201    
Shares purchased from contributions to the ESPP 457,362 $ 2 457,360  
Shares purchased from contributions to the ESPP (in shares)   178,003    
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 placement, net of issuance costs (in shares)   3,333,333    
Issuance of shares in an at-the-market ("ATM") placement, net of issuance costs 4,557,693 $ 21 4,557,672  
Issuance of shares in an at-the-market ("ATM") placement, net of issuance costs (in shares)   2,059,625    
Net loss (38,399,089)     (38,399,089)
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") 7,656,857   7,656,857  
Stock-based compensation - employee stock purchase plan ("ESPP") 329,461   329,461  
Stock-based compensation - performance share units ("PSUs") (88,348)   (88,348)  
Issuance of shares for RSUs   $ 12 (12)  
Issuance of shares for RSUs (in shares)   1,194,439    
Shares purchased from contributions to the ESPP 417,546 $ 3 417,543  
Shares purchased from contributions to the ESPP (in shares)   275,312    
Issuance of shares in an at-the-market ("ATM") placement, net of issuance costs 53,556,202 $ 266 53,555,936  
Issuance of shares in an at-the-market ("ATM") placement, net of issuance costs (in shares)   26,618,855    
Net loss (31,832,086)     (31,832,086)
Ending balance at Dec. 31, 2020 $ 49,052,506 $ 614 $ 344,024,638 $ (294,972,746)
Ending balance (in shares) at Dec. 31, 2020   61,292,412