Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Warrant Activity (Details)

v3.20.4
Stockholders' Equity - Summary of Warrant Activity (Details) - Warrant - USD ($)
6 Months Ended
Oct. 31, 2020
Apr. 30, 2020
Oct. 31, 2020
Number of Shares      
Balance Outstanding, April 30, 2020 (in shares)     566,223
Granted (in shares)     0
Warrants exercised (in shares)     (192,049)
Surrendered (in shares)     0
Expired (in shares)     0
Balance Outstanding, October 31, 2020 (in shares) 374,174 566,223 374,174
Exercisable, October 31, 2020 (in shares) 374,174   374,174
Weighted Average Exercise Price      
Balance Outstanding, April 30, 2020 (in dollars per share)     $ 6.22
Granted (in dollars per share)     0
Exercised (in dollars per share)     5.60
Surrendered (in dollars per share)     0
Expired (in dollars per share)     0
Balance Outstanding, October 31, 2020 (in dollars per share) $ 6.37 $ 6.22 6.37
Exercisable, October 31, 2020 (in dollars per share) $ 6.37   $ 6.37
Weighted Average Remaining Contractual Term      
Weighted Average Remaining Contractual Term 2 years 4 months 20 days 3 years 2 months 1 day  
Weighted Average Remaining Contractual Term, Exercisable 2 years 4 months 20 days    
Aggregate Intrinsic Value      
Average Intrinsic Value $ 1,125,177 $ 950,100 $ 1,125,177
Aggregate Intrinsic Value, Exercisable $ 1,125,177   $ 1,125,177