20. STOCK BASED COMPENSATION

The 2020 Incentive Award Plan (the “2020 Plan”) allows for the award of incentive and nonqualified stock options, restricted stock, and other stock-based awards to employees, officers, directors, consultants, and advisers of the Company. As of December 31, 2023, the number of shares available for future issuance is 28,210,509 under the 2020 Plan. In addition, the number of shares of common stock available for issuance under the 2020 Plan is subject to an annual increase on the first day of each calendar year beginning on January 1, 2021 and ending on and including January 1, 2030 equal to the lesser of (i) 5% of the aggregate number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the Board of Directors. On January 1, 2024, 16,263,584 shares were added as available for issuance to the 2020 Plan.

Stock Options

The option activity of the Plans for the three months ended March 31, 2024, is as follows (shares in thousands):

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There was no options exercised during the three months ended March 31, 2024, as such, there is no aggregate intrinsic value of options exercised during the three months ended March 31, 2024. During the three months ended March 31, 2023, the aggregate intrinsic value of options exercised was $0.5 million.

The total stock-based compensation expense related to stock options was $0.3 million during the three months ended March 31, 2024, and $0.4 million during the three months ended March 31, 2023.

Total unrecognized stock-based compensation expense related to unvested stock options at March 31, 2024 aggregated $0.3 million and is expected to be recognized over a weighted-average period of 0.4 years.

Restricted Stock Awards

In connection with acquisitions, the Company has granted restricted stock awards (“RSAs”) that are considered post-combination expense and accounted for as stock-based compensation as the shares vest.

The activity for stock subject to vesting as of March 31, 2024, is as follows (shares in thousands):

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There was an immaterial amount of stock-based compensation expense related to RSAs during the three months ended March 31, 2024 and $0.2 million during the three months ended March 31, 2023, respectively. At March 31, 2024, the RSAs were fully vested.

Restricted Stock Units

Restricted Stock Units (“RSUs”) awarded to employees and non-employees generally vest over four years from the anniversary date of the grant, with one-year cliff vesting and quarterly vesting thereafter, provided service with the Company is not terminated. The fair value of RSUs is equal to the estimated fair market value of the Company’s Common Stock on the date of grant.

RSU activity under the 2020 Plan for the three months ended March 31, 2024, is as follows (shares in thousands):

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The total stock-based compensation expense related to RSUs was $7.5 million during the three months ended March 31, 2024, and $8.7 million during the three months ended March 31, 2023. Total unrecognized compensation costs related to unvested RSUs at March 31, 2024 is $41.2 million and is expected to be recognized over a period of 2.3 years.

RSUs include awards that vest subject to certain performance and market-based criteria.

Performance-Based Restricted Stock Units (included above)

During the year ended December 31, 2021, 670,000 performance-based RSUs were granted to key employees of the Company. These awards vest upon the achievement of certain performance milestones by the Company and prescribed service milestones by the employee. During the three months ended March 31, 2024, no performance-based RSUs vested or were forfeited. As of March 31, 2024, 150,000 performance-based RSUs remain outstanding.

During the year ended December 31, 2020, 124,300 performance-based RSUs were granted to a key employee of the Company. This award vests upon the achievement of certain performance milestones by the Company and prescribed service milestones by the employee. During the year ended December 31, 2023, 124,300 performance-based RSUs were forfeited. As of December 31, 2023, no performance-based RSUs remain outstanding.

Market-Based Restricted Stock Units (included above)

In October 2021 the Compensation Committee of the Company’s Board of Directors awarded certain executive officers a total of up to 9,070,269 market-based RSUs. These RSUs will vest and result in the issuance of shares of Common Stock based on continuing employment and the achievement of certain market conditions set by the Company.

During the year ended December 31, 2021, one of the executive officers resigned from the Company, forfeiting his market-based RSUs. As the service condition was not met prior to his resignation, no stock-based compensation expense was recorded for this award. No market-based RSUs vested or were forfeited during the year ended December 31, 2023 or during the three months ended March 31, 2024. As of March 31, 2024, 6,802,702 market-based RSUs remain outstanding.

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Bonus Program

The Company’s bonus program allows the bonus to be paid out in RSUs, cash, or a combination.

The Company’s 2023 bonus program ("2023 Bonus Program") was granted in dollar bonus amounts, which were paid out in RSUs during the three months ended March 31, 2024. The number of RSUs awarded was determined using the closing price of the Company's Common Stock on the date of the Board's final certification of the Company's performance attainment and awards to be issued to each employee. The Company accounted for these awards as liability-based awards until the awards were achieved, at which point the Company accounted for these awards as equity-based awards. During the three months ended March 31, 2023, the Company recognized $1.6 million of stock-based compensation expense associated with liability classified awards related to the 2023 Bonus Program.

The Company’s 2024 bonus program (“2024 Bonus Program”) is expected to be paid out in RSUs determined using the closing price of the Company's Common Stock on the date of the Board's final certification of the Company's performance attainment and awards to be issued to each employee. The Company has accounted for these awards as liability-based awards, since the monetary

value of the obligation associated with the award is based predominantly on a fixed monetary amount known at inception, and it has an unconditional obligation that it must or may settle by issuing a variable number of its equity shares. The Company will recognize stock-based compensation expense over the employees’ requisite service period, based on the expected attainment of the Company-wide targets. As of March 31, 2024, the Company has accrued $0.5 million associated with these awards, which is recorded in accrued expenses and other current liabilities in the condensed consolidated balance sheets.

Stock-Based Compensation Expense

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Total stock-based compensation expense related to all of the Company’s stock-based awards granted is reported in the condensed consolidated statements of operations as follows (in thousands):

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There were 37,038,487 shares available for award under the 2020 Plan at March 31, 2024.