Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Stock-based Compensation - Stock Option Activity (Details)

v3.21.2
Note 6 - Stock-based Compensation - Stock Option Activity (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2021
Mar. 31, 2021
Jun. 30, 2020
Mar. 31, 2020
Jun. 30, 2021
Jun. 30, 2020
Outstanding, shares (in shares) 1,515,000 1,395,000 1,220,000 1,349,000 1,395,000 1,349,000
Outstanding, weighted average exercise price (in dollars per share) $ 0.53 $ 0.31 $ 0.24 $ 0.23 $ 0.31 $ 0.23
Options granted, shares (in shares) 127,500 145,000 10,000 0 272,500 10,000
Options granted, weighted average exercise price (in dollars per share) $ 2.85 $ 2.62 $ 0.15      
Options exercised, shares (in shares) (360,000) (25,000) 0   (385,000) 0
Options exercised, weighted average exercise price (in dollars per share) $ 0.22 $ 0.14        
Options expired, shares (in shares) (20,000)   (10,000) (129,000)    
Options expired, weighted average exercise price (in dollars per share) $ 0.17   $ 0.19 $ 0.17    
Outstanding, weighted average remaining contractual term (Month) 6 years   3 years 9 months      
Outstanding, aggregate intrinsic value $ 2,876,868   $ 37,353   $ 2,876,868 $ 37,353
Exercisable, shares (in shares) 780,000   1,207,000   780,000 1,207,000
Exercisable, weighted average exercise price (in dollars per share) $ 0.33   $ 0.24   $ 0.33 $ 0.24
Exercisable, weighted average remaining contractual term (Month) 3 years 2 months   3 years 8 months      
Exercisable, aggregate intrinsic value $ 2,194,843   $ 36,703   $ 2,194,843 $ 36,703
Outstanding, weighted average exercise price (in dollars per share) $ 0.86 $ 0.53 $ 0.24 $ 0.24 $ 0.86 $ 0.24
Outstanding, shares (in shares) 1,262,500 1,515,000 1,220,000 1,220,000 1,262,500 1,220,000
Outstanding, weighted average exercise price (in dollars per share) $ 0.86 $ 0.53 $ 0.24 $ 0.24 $ 0.86 $ 0.24