Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Warrants (Tables)

v3.21.1
Note 4 - Warrants (Tables)
3 Months Ended
Mar. 31, 2021
Notes Tables  
Schedule of Warrants or Rights, Assumptions Used [Table Text Block]
   

March 31, 2021

   

December 31, 2020

 

Risk-free interest rate

  0.1% to 0.7%     0.1% to 0.3%  

Volatility

  96.5% to 136.1%     113.7% to 127.4%  

Expected life (years)

  0.9 to 4.5     1.1 to 4.6  

Dividend yield

  —%     —%  
Schedule of Warrant Activity [Table Text Block]
   

Number of Shares

   

Range of Warrant Exercise

   

Weighted Average

   

Weighted Average Remaining Contractual

 
   

Under Warrant

   

Price per Share

   

Exercise Price

   

Life (Years)

 

Balance at January 1, 2021

    2,733,645     $ 6.30     $ 16.80     $ 9.45       3.6  

Granted

                             

Exercised

    (10,000 )     6.30       6.30       6.30        

Expired

                             

Balance at March 31, 2021

    2,723,645     $ 6.30     $ 16.80     $ 9.46       3.4  

Exercisable at March 31, 2021

    2,723,645     $ 6.30     $ 16.80     $ 9.46       3.4