v3.26.1
Note 10 - Equity Incentive Plans (Tables)
6 Months Ended
Jun. 30, 2026
Notes Tables  
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
          

Weighted

      

Weighted

 
  

Shares

  

Number of

  

Option Average

  

Unvested

  

RSU Average

 
  

Available

  

Options

  

Exercise

  

RSU Shares

  

Grant Date

 
  

For Grant

  

Outstanding

  

Price

  

Outstanding

  

Fair Value

 
                     

Balance as of January 1, 2026

  10,875,110   25,407,299  $1.96   5,733,306  $0.70 

Granted

  (8,226,220)  5,438,040  $0.68   2,788,180  $0.68 

Exercised

     (111,891) $0.51     $ 

Released

       $   (1,596,401) $0.79 

Forfeited

  839,948   (479,584) $0.86   (360,364) $0.92 

Canceled

  3,604,116   (3,614,052) $3.49     $ 
                     

Balance as of June 30, 2026

  7,092,954   26,639,812  $1.52   6,564,721  $0.66 
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
  

Six Months Ended June 30,

 
  

2026

  

2025

 
         

Risk-free interest rate

  3.9% -4.0%  4.1% - 4.4% 

Expected term (in years)

  6.0   5.5 -6.0 

Expected volatility

  118.4%  125.8% -128.6% 

Dividend yield

  %  %
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
  

Three Months Ended June 30,

  

Six Months Ended June 30,

 
  

2026

  

2025

  

2026

  

2025

 
                 

Research and development

 $646  $1,494  $1,458  $3,196 

General and administrative

  644   627   1,314   1,384 

Total stock-based compensation

 $1,290  $2,121  $2,772  $4,580