Annual report pursuant to Section 13 and 15(d)

Note 1 - Organization and Summary of Significant Accounting Policies (Tables)

v3.21.1
Note 1 - Organization and Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2020
Notes Tables  
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
   
2020
   
2019
 
Expected volatility
 
86%
-
102%
   
76%
-
93%
 
Weighted-average volatility
 
 
92%
 
   
 
86%
 
 
Expected forfeiture rate
 
7.0%
-
10.5%
   
15.1%
-
15.5%
 
Expected term (in years)
 
5.5
-
6.0
   
3.5
-
6.0
 
Risk-free rate
 
0.4%
-
1.5%
   
2.4%
-
2.5%
 
Expected dividends