Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details)

v3.22.1
Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details)
 3 Months Ended
Mar. 31, 2022
$ / shares
shares
Outstanding at beginning of period (in shares) | shares 919,790
Outstanding at beginning of period, weighted average exercise price (in dollars per share) | $ / shares $ 5.67
Granted (in shares) | shares 2,500
Granted, weighted average exercise price (in dollars per share) | $ / shares $ 0.97
Cancelled/Forfeited (in shares) | shares (27,455)
Cancelled/Forfeited, weighted average exercise price (in dollars per share) | $ / shares $ 6.29
Expired (in shares) | shares (6,185)
Expired, weighted average exercise price (in dollars per share) | $ / shares $ 64.17
Outstanding at end of period (in shares) | shares 888,650
Outstanding at end of period, weighted average exercise price (in dollars per share) | $ / shares $ 5.23
Outstanding, weighted average remaining contractual life (Year) 6 years 3 months 18 days
Exercisable at end of period (in shares) | shares 634,485
Exercisable at end of period, weighted average exercise price (in dollars per share) | $ / shares $ 6.73
Exercisable, weighted average remaining contractual life (Year) 5 years 1 month 6 days