v3.26.1
Stock-Based Compensation​ (Tables)
6 Months Ended
Jun. 30, 2026
Share-Based Payment Arrangement [Abstract]  
Schedule of Stock Option Activity
A summary of the Company’s stock option activity is as follows:
Number of
Shares
Weighted
Average
Exercise
Price
Weighted
Average
Remaining
Contractual
Life (Years)
Aggregate
Intrinsic
Value
(In millions)
Outstanding as of December 31, 2025
1,623,752 $0.14 4.8$12.0 
Exercised(529,690)0.14 3.3 
Expired/forfeited— — 
Outstanding as of June 30, 2026
1,094,062 0.14 4.35.0 
Vested and exercisable as of June 30, 2026
1,094,062 0.14 4.35.0 
Schedule of Share-based Payment Arrangement, Restricted Stock Unit, Activity
A summary of the Company’s RSU activity is as follows:
Number of
Shares
Weighted
Average
Grant Fair Value
Outstanding as of December 31, 2025
34,166,124 $7.36 
Granted27,057,890 6.44 
Performance based adjustment (1)
(96,039)10.77 
Vested(11,627,479)6.83 
Forfeited (1,722,075)8.86 
Outstanding as of June 30, 2026
47,778,421 6.92 
(1) Represents units adjusted for the vesting of the PSUs (defined below) granted in 2024 and 2025.
Schedule of Share-Based Payment Award, Valuation Assumptions
The following assumptions were used to estimate the fair value, using the Monte Carlo simulation, of the PSUs:
May 15,
2026
February 9,
2026
Stock price$6.05 $7.37 
Term (in years)3.03.0
Risk-free interest rate4.1 %3.5 %
Volatility85.1 %86.7 %
Dividend yield0.0 %0.0 %
Schedule of Share-Based Payment Award, Valuation Assumptions The following table sets forth the key assumptions and fair value results for each award granted in the Company’s six-month offering period:
InputJune 1,
2026
Stock price$6.84 
Term (in years)0.5
Risk-free interest rate3.8 %
Volatility75.5 %
Dividend yield0.0 %
Grant date fair value per share$2.50 
Schedule of Share-based Payment Arrangement, Expensed and Capitalized, Amount
The following table presents stock-based compensation expense included in each respective expense category in the condensed consolidated statements of operations (in millions):
Three Months Ended June 30,Six Months Ended June 30,
2026202520262025
Research and development$41.2 $22.9 $73.3 $34.0 
General and administrative44.4 28.9 82.7 47.9 
Total stock-based compensation expense$85.6 $51.8 $156.0 $81.9