8. Stock-Based Compensation

In 2014, the Company adopted the amended and restated Terrestrial Energy Inc. 2014 Stock Options Plan (“the 2014 Plan”). In connection with the Company’s redomestication to Delaware, outstanding awards under the 2014 Plan were assumed by the Terrestrial Energy Delaware Inc. 2024 Stock Option Plan, which was most recently amended and restated in October 2024, as the Terrestrial Energy Inc. Second Amended and Restated 2024 Stock Option Plan. In October 2025, the Company adopted the 2025 Equity Incentive Plan, effective immediately prior to the closing of the Business Combination (the “Current Plan”). As of June 30, 2026, the Current Plan authorizes the Company to award equity awards resulting in the issuance of up to 38,347,872 shares of common stock. The Current Plan provides for grants of incentive stock options, non-qualified stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights and other awards to employees, non-employee directors, consultants and advisors of the Company. The Current Plan is designed to promote the interests of the Company using equity investment interests to attract, motivate, and retain individuals. The Current Plan is administered by the Board of Directors. The Board determines the type, number, vesting requirements and other features and conditions of such awards. Generally, stock options granted from the Current Plan have a contractual term of ten years from the date of the grant and vest over one to three years, subject to the discretion of the Compensation Committee.

The Company has recorded stock-based compensation expense for options of $423 and $214 for the three months ended June 30, 2026 and 2025, respectively. The Company has recorded stock-based compensation expense for options of $863 and $394 for the six months ended June 30, 2026 and 2025, respectively. As of June 30, 2026, total compensation expense related to awards not yet recognized was approximately $2,782 which is expected to be recognized over a weighted average period of 1.8 years.

The Company recorded stock-based compensation expense for RSU awards of $2,463 and $0 for the three months ended June 30, 2026 and 2025, respectively. The Company recorded stock-based compensation expense for RSU awards of $4,784 and $0 for the six months ended June 30, 2026 and 2025, respectively. The total unrecognized RSU expense as of June 30, 2026 was $7,384 with a weighted-average period over which it is to be recognized of 1.2 years.