v3.21.2
Stockholders’ Equity and Stock-Based Compensation (Tables)
6 Months Ended
Jun. 30, 2021
Share-based Payment Arrangement [Abstract]  
Schedule of Warrant Activity
A summary of the Company’s warrant activity during the six months ended June 30, 2021 was as follows:
Shares of Stock under WarrantsWeighted-
Average
Exercise
Price
Weighted-
Average
Remaining
Contractual
Term
Aggregate
Intrinsic
Value
Outstanding at January 1, 202115,174,000 $2.34 3.76$26,841,000 
Granted— 
Exercised(10,789,000)0.88 58,175,000 
Canceled(24,000)
Outstanding at June 30, 2021
4,361,000 $5.95 2.27$6,904,000 
Summary of Stock Option Activity
A summary of the Company’s stock option activity during the six months ended June 30, 2021 was as follows:   
Shares of Stock under Stock OptionsWeighted-
Average
Exercise
Price
Weighted-
Average
Remaining
Contractual
Term
Aggregate
Intrinsic
Value
Outstanding at January 1, 20215,290,000 $1.91 8.7$10,178,000 
Granted5,067,000 7.48 
Exercised(162,000)2.55 $1,102,000 
Canceled(645,000)2.64 
Outstanding at June 30, 2021
9,550,000 $4.81 9.16$27,042,000 
Vested and exercisable at June 30, 2021
1,896,000 $3.86 8.02$7,555,000 
Summary of Recognized Stock-Based Compensation Expense
The Company recognized stock-based compensation expense for the periods presented as follows: 
 Three Months Ended
June 30,
Six Months Ended
June 30,
2021202020212020
Research and development$384,000 $66,000 $465,000 $133,000 
General and administrative1,374,000 262,000 1,664,000 523,000 
Total stock-based compensation expense$1,758,000 $328,000 $2,129,000 $656,000 
Schedule of Weighted-Average Assumptions in Black -Scholes Option Pricing Model
The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants during the periods presented were as follows:
Three Months Ended
June 30,
Six Months Ended
June 30,
2021202020212020
Risk-free interest rate1.1 %0.4 %1.1 %1.1 %
Expected volatility80.4 %77.9 %80.4 %72.2 %
Expected term (in years)6.05.56.05.9
Expected dividend yield0.0 %0.0 %0.0 %0.0 %