| Share-Based Compensation Arrangements by Share-Based Payment Award, Restricted Stock Units, Vested and Expected to Vest |
Stock option activity during the year ended December 31, 2025, consisted of the following (in thousands, except for share and per share data): | | | | | | | | | | | | | Stock options | Weighted-Average Exercise Price | Weighted-Average Remaining Contractual Term (Years) | | Outstanding as of December 31, 2024 | 498,661 | $ | 5.65 | 8.92 | | Granted | 1,166,670 | 1.53 | | | Forfeited | (63,771) | 2.43 | | | Expired | (10,907) | 5.81 | | | Outstanding as of December 31, 2025 | 1,590,653 | 2.76 | 8.86 | | Vested and exercisable as of December 31, 2025 | 209,180 | $ | 5.98 | | 7.75 |
| | | | | | | | | | Number of Units | Weighted-Average Grant Date Fair Value | | Unvested as of December 31, 2024 | 643,591 | | $ | 5.66 | | Granted | 1,477,107 | | 2.04 | | Vested | (4,398) | | 6.12 | | Forfeited | (179,993) | | 3.37 | | Unvested as of December 31, 2025 | 1,936,307 | | $ | 3.11 |
A summary of the unvested shares as of December 31, 2025, and changes during the year ended December 31, 2025, is presented below. | | | | | | | | | | Number of Units | Weighted-Average Grant Date Fair Value | | Unvested as of December 31, 2024 | 1,886,825 | $ | 5.39 | | Granted | 3,643,711 | 2.05 | | Vested | (546,399) | 5.57 | | Withheld for settlement of taxes | (197,358) | 5.90 | | Forfeited | (483,937) | 2.81 | | Unvested as of December 31, 2025 | 4,302,842 | $ | 2.81 |
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| Stock-based Compensation Expense |
The stock-based compensation expense for the above stock awards under the 2022 Plan as well as Parent Equity Awards is included in selling, general and administrative expenses: | | | | | | | | | | Year Ended
December 31, | | 2025 | 2024 | | 2022 Plan | $ | 6,370 | | $ | 6,128 | | | Parent equity awards | 129 | | 324 | | | $ | 6,499 | | $ | 6,452 | |
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