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Stockholders' Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Subsidiary, Sale of Stock [Line Items] |
Summary of the Company's RSU activity | The following table summarizes the Company’s Service-Based RSU activities for the year ended December 31, 2024:
​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted
​ | ​ | ​ | ​ | Average
​ | ​ | Number of | ​ | Fair Value at
​ |  | Shares |  | Grant Date
RSU outstanding and unvested as of December 31, 2023 |  | 399,709 | ​ | $ | 8.10
Granted |  | 1,889,502 | ​ | $ | 2.83
Vested |  | (347,482) | ​ | $ | 8.64
Forfeited or expired |  | (13,129) | ​ | $ | 4.57
RSU outstanding and unvested as of December 31, 2024 |  | 1,928,600 | ​ | $ | 2.86
Summary of compensation expense and related income tax benefit related to the stock-based compensation expense recognized | The following table summarizes the compensation expense and related income tax benefit related to the Company’s stock-based compensation arrangements recognized in the accompanying consolidated statements of operations during the periods presented (in thousands):
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year Ended December 31,
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | 2022 |  | 2023 |  | 2024
Stock-based compensation expense, net of $0 tax in 2022, 2023 and 2024 | ​ | $ | 26,473 | ​ | $ | 23,336 | ​ | $ | 10,803
Stonepeak Warrant |
Subsidiary, Sale of Stock [Line Items] |
Schedule of fair value inputs |
​ | ​ | ​ | ​ | ​
​ |  | December 12, 2023 |  | December 12, 2023
Exercise price | ​ | 5.50 | ​ | 6.50
Dividend yield |  | 0.0% | ​ | 0.0%
Expected volatility |  | 72.96% | ​ | 72.96%
Risk-free interest rate |  | 4.22% | ​ | 4.22%
Expected term in years |  | 8.5 |  | 8.5
Schedule of warrant activity | ​
​ | ​ | ​
​ | ​ | Warrant
​ |  | Shares
Outstanding and unexercised as of December 31, 2023 |  | 20,000,000
Granted |  | 28,918
Exercised |  | —
Outstanding and unexercised as of December 31, 2024 |  | 20,028,918
​
Amazon Warrant |
Subsidiary, Sale of Stock [Line Items] |
Schedule of fair value inputs | ​
​ | ​ | ​ | ​ | ​
​ |  | April 16, 2021 |  | June 14, 2021
Dividend yield |  | 0.0% | ​ | 0.0%
Expected volatility |  | 66.46% | ​ | 67.97%
Risk-free interest rate |  | 1.59% | ​ | 1.49%
Expected term in years |  | 10.0 |  | 9.8
Schedule of warrant activity | The following table summarizes the Amazon Warrant activities for the year ended December 31, 2024:
​ | ​ | ​
​ | ​ | Warrant
​ |  | Shares
Outstanding and unvested as of December 31, 2023 |  | 37,613,035
Granted |  | —
Vested |  | (7,640,152)
Outstanding and unvested as of December 31, 2024 |  | 29,972,883
Service Based Stock Options |
Subsidiary, Sale of Stock [Line Items] |
Summary of stock option activity | The following table summarizes the Company’s service-based stock option activities for the year ended December 31, 2024:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Average | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted | ​ | Remaining | ​ | Aggregate
​ | ​ | ​ | ​ | Average | ​ | Contractual | ​ | Intrinsic
​ | ​ | Number of | ​ | Exercise | ​ | Term | ​ | Value
​ |  | Shares |  | Price |  | (in years) |  | (in thousands)
Options outstanding as of December 31, 2023 |  | 12,560,577 | ​ | $ | 5.68 |  |  |  | ​ |
Granted |  | 3,216,932 | ​ | $ | 2.83 | ​ | ​ | ​ | ​ | ​
Exercised |  | (35,911) | ​ | $ | 1.71 | ​ | ​ | ​ | ​ | ​
Forfeited or expired |  | (825,986) | ​ | $ | 7.40 | ​ | ​ | ​ | ​ | ​
Options outstanding as of December 31, 2024 |  | 14,915,612 | ​ | $ | 4.98 | ​ | 6.56 | ​ | $ | 1,215
Options exercisable as of December 31, 2024 |  | 9,879,896 | ​ | $ | 5.69 | ​ | 5.42 | ​ | $ | 1,213
Options vested and expected to vest as of December 31, 2024 |  | 14,915,612 | ​ | $ | 4.98 | ​ | 6.56 | ​ | $ | 1,215
Schedule of assumptions used to estimate the fair value of each award using the Black-Scholes option pricing model | ​ The fair value of each service-based stock option granted was estimated as of the date of grant using the Black-Scholes option pricing model and using the following assumptions:
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year Ended December 31,
​ |  | 2022 |  | 2023 |  | 2024
Dividend yield |  | 0.0% | ​ | 0.0% | ​ | 0.0%
Expected volatility |  | 73.7% to 76.9% | ​ | 75.2% to 76.6% | ​ | 76.5% to 76.9%
Risk-free interest rate |  | 1.52% to 4.34% | ​ | 3.68% to 4.73% | ​ | 4.18% to 4.39%
Expected life in years |  | 5.6 to 5.9 |  | 5.9 to 6.2 |  | 6.1 to 6.2
Performance-Based Stock Options |
Subsidiary, Sale of Stock [Line Items] |
Summary of stock option activity | The following table summarizes the Company’s performance-based stock option activities for the year ended December 31, 2024:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Average | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted | ​ | Remaining | ​ | Aggregate
​ | ​ | ​ | ​ | Average | ​ | Contractual | ​ | Intrinsic
​ | ​ | Number of | ​ | Exercise | ​ | Term | ​ | Value
​ |  | Shares |  | Price |  | (in years) |  | (in thousands)
Options outstanding as of December 31, 2023 |  | 1,615,000 | ​ | $ | 6.77 | ​ |  |  | ​ |
Granted |  | — | ​ | $ | — | ​ | ​ | ​ | ​ | ​
Exercised |  | — | ​ | $ | — | ​ | ​ | ​ | ​ | ​
Forfeited or expired |  | (25,000) | ​ | $ | 6.77 | ​ | ​ | ​ | ​ | ​
Options outstanding as of December 31, 2024 |  | 1,590,000 | ​ | $ | 6.77 | ​ | 6.94 | ​ | $ | —
Options vested and exercisable as of December 31, 2024 |  | 397,500 | ​ | $ | 6.77 | ​ | 6.94 | ​ | $ | —
Schedule of assumptions used to estimate the fair value of each award using the Black-Scholes option pricing model | The fair value of each performance-based stock option granted was estimated as of the date of grant using the Black-Scholes option pricing model and using the following assumptions:
​ | ​ | ​
​ | ​ | ​
​ |  | December 7, 2021
Dividend yield | ​ | 0.0%
Expected volatility | ​ | 77.1%
Risk-free interest rate | ​ | 1.36%
Expected life in years | ​ | 6.2
Market Based Stock Options |
Subsidiary, Sale of Stock [Line Items] |
Summary of stock option activity | The following table summarizes the Company’s market-based stock option activities for the year ended December 31, 2024:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Average | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted | ​ | Remaining | ​ | Aggregate
​ | ​ | ​ | ​ | Average | ​ | Contractual | ​ | Intrinsic
​ | ​ | Number of | ​ | Exercise | ​ | Term | ​ | Value
​ |  | Shares |  | Price |  | (in years) |  | (in thousands)
Options outstanding as of December 31, 2023 |  | 3,650,000 | ​ | $ | 6.77 | ​ |  |  | ​ |
Granted |  | — | ​ | $ | — | ​ | ​ | ​ | ​ | ​
Exercised |  | — | ​ | $ | — | ​ | ​ | ​ | ​ | ​
Forfeited or expired |  | — | ​ | $ | 6.77 | ​ | ​ | ​ | ​ | ​
Options outstanding as of December 31, 2024 |  | 3,650,000 | ​ | $ | 6.77 | ​ | 6.94 | ​ | $ | —
Options vested and exercisable as of December 31, 2024 |  | — | ​ | $ | — | ​ | — | ​ | $ | —
Schedule of assumptions used to estimate the fair value of each award using the Black-Scholes option pricing model | ​
​ | ​ | ​
​ | ​ | ​
​ |  | December 7, 2021
Dividend yield | ​ | 0.0%
Expected volatility | ​ | 67.8%
Risk-free interest rate | ​ | 1.5%
Expected life in years | ​ | 10.0

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