2. Stock Plans
The following table summarizes option activity:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted |
|
|
|
|
|
|
|
Weighted |
|
Average |
|
|
|
|
|
|
|
Average |
|
Remaining |
|
Aggregate |
|
|
|
|
Exercise |
|
Option |
|
Intrinsic |
|
|
Options (in |
|
Price per |
|
Term |
|
Value |
|
|
thousands) |
|
share |
|
(in years) |
|
(in thousands) |
Outstanding at December 31, 2020 |
|
28 |
|
$ |
242.70 |
|
6.35 |
|
$ |
— |
Granted |
|
670 |
|
|
4.02 |
|
|
|
|
|
Forfeited or expired |
|
(6) |
|
|
137.74 |
|
|
|
|
|
Outstanding at June 30, 2021 |
|
692 |
|
$ |
12.46 |
|
9.49 |
|
$ |
— |
Exercisable at June 30, 2021 |
|
22 |
|
$ |
272.90 |
|
5.50 |
|
$ |
— |
No options to purchase common shares were granted during the three-month period ended June 30, 2021.
The following table summarizes the stock-based compensation expense recorded for awards under our stock option plans (in thousands):
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Three Months Ended |
|
Six Months Ended |
(in thousands) |
|
June 30, |
|
June 30, |
|
|
2021 |
|
2020 |
|
2021 |
|
2020 |
Research and development |
|
$ |
214 |
|
$ |
— |
|
$ |
334 |
|
$ |
— |
Selling, general and administrative |
|
|
233 |
|
|
79 |
|
|
361 |
|
|
(5) |
Total stock-based compensation |
|
$ |
447 |
|
$ |
79 |
|
$ |
695 |
|
$ |
(5) |
We use the Black-Scholes-Merton option-pricing model with the following assumptions to estimate the fair value of our stock options:
|
|
|
|
|
|
|
|
|
|
|
|
Three Months Ended |
|
Six Months Ended |
|
|
|
June 30, |
|
June 30, |
|
|
|
2021 |
|
2020 |
|
2021 |
|
2020 |
|
Weighted-average risk-free interest rate |
|
— |
% |
0.4 |
% |
0.5 |
% |
0.4 |
% |
Expected dividend payments |
|
— |
|
— |
|
— |
|
— |
|
Expected holding period (years) 1 |
|
— |
|
5.8 |
|
5.5 |
|
5.8 |
|
Weighted-average volatility factor 2 |
|
— |
|
1.04 |
|
1.14 |
|
1.04 |
|
Estimated forfeiture rates for options granted 3 |
|
— |
% |
28 |
% |
30 |
% |
28 |
% |
(1) |
Expected holding period is based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and the expectations of future employee behavior. |
(2) |
Weighted average volatility is based on the historical volatility of our common stock. |
(3) |
Estimated forfeiture rates are based on historical data. |
As of June 30, 2021, there was approximately $0.9 million of total unrecognized compensation expense related to non-vested stock options. This expense is expected to be recognized over a weighted-average period of approximately 1.4 years.
|