10. Stock-based Compensation

In October 2020, the Company’s stockholders approved the Company’s 2020 Incentive Award Plan (“2020 Plan”). The 2020 Plan initially provided for the issuance of up to 7,924,000 shares of common stock and for the grant of incentive stock options or other incentive awards to employees, officers, directors and consultants of the Company. The number of shares of common stock that may be issued under the 2020 Plan is subject to increase on the first day of each calendar year 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 or ii) such smaller number of shares as is determined by the board of directors. Through December 31, 2025, the shares available under the 2020 Plan have been increased by an aggregate of 20,845,291 shares. As of December 31, 2025, 5,085,914 shares of common stock were available for future issuance under the 2020 Plan. In January 2026, the number of shares of common stock available for future issuance under the 2020 Plan was increased by 3,906,339 shares.

The 2020 Plan replaced and is the successor of the Company’s 2013 Equity Incentive Plan, as amended (“2013 Plan”). In the event of any cancellation of an outstanding option award under the 2013 Plan, the shares underlying the cancelled option award will be made available for grant under the 2020 Plan.

Stock Options

During the years ended December 31, 2025 and 2024, the Company granted to employees and members of the board of directors 3,386,028 and 3,213,550 stock options with an aggregate grant date fair value of $7,433 and $9,622, respectively.

The aggregate intrinsic value of options granted is calculated as the difference between the exercise price of the options and the estimated fair value of the common stock for those options that had exercise prices lower than the fair value of the common stock.

Option awards granted to employees generally vest over a service period of four years and option awards granted to members of the board of directors generally vest over a service period of one year or three years. All options have a contractual term of ten years. As of December 31, 2025, total unrecognized compensation expense related to stock option awards was $13,236, which amount is being recognized over a remaining weighted average period of 2.1 years.

The weighted average grant date fair value per option granted during the years ended December 31, 2025 and 2024 was $2.20 and $2.99, respectively. The fair value of each award was estimated using Black-Scholes based on the following weighted average assumptions:

Restricted Stock Units

During the year ended December 31, 2025 and 2024, the Company granted 1,091,064 and 1,126,100 restricted stock units to employees and the board of directors with an aggregate grant date fair market value of $3,372 and $4,557, respectively. The restricted stock unit awards vest in three annual installments. During the years ended December 31, 2025 and 2024, the Company issued 1,216,965 and 927,932 shares of common stock upon the vesting and settlement of restricted stock units. During the years ended December 31, 2025 and 2024, 150,087 and 12,633 restricted stock units were cancelled due to employee terminations.

As of December 31, 2025, total unrecognized compensation expense related to restricted stock unit awards was $3,620, which amount is being recognized over a remaining weighted average period of 1.1 years.

Performance-based Restricted Stock Units

During the year ended December 31, 2022 the Company granted 724,970 performance-based restricted stock units (“2022 PSUs”) to employees with an aggregate grant fair value of $5,298. The performance period for the 2022 PSUs ran from February 1, 2022 through January 31, 2025 to achieve up to six defined performance metrics. The Company achieved two metrics which resulted in 50% of the grant date fair value being recognized as expense. Of the total 2022 PSUs granted, 25% vested on January 31, 2025, and 25% will vest on January 31, 2026 subject to the employee's continued employment through the applicable vesting date. The Company recorded compensation expense of $359 and $2,201 for the years ended December 31, 2025 and 2024, respectively. Expense is being recognized through January 31, 2026 for the 2022 PSUs that may vest on that date.

During the year ended December 31, 2024, the Company granted 1,057,900 performance-based restricted stock units (“2024 PSUs”) to employees with an aggregate grant date fair value of $4,401. The 2024 PSUs provide for a performance period from February 1, 2024 through January 31, 2027 to achieve up to four defined performance metrics. The percentage of 2024 PSUs eligible to vest will be determined based on the number of metrics achieved during the performance period and may range from 0% to 200%. As of December 31, 2025, two of the 2024 PSU metrics were deemed probable of achievement resulting in expense recognition of 75% of the 2024 PSU grant date value. Compensation expense is being recognized from the grant date through the final vest date of January 31, 2027. The Company recorded compensation expense of $1,100 and $1,009 for the years ended December 31, 2025 and 2024, respectively.

During the year ended December 31, 2025, the Company granted 1,045,600 performance-based restricted stock units (“2025 PSUs”) to employees with an aggregate grant date fair value of $3,200. The 2025 PSUs provide for a performance period from February 1, 2025 through January 31, 2028 to achieve up to four defined performance metrics. The percentage of 2025 PSUs eligible to vest will be determined based on the number of metrics achieved during the performance period and may range from 0% to 200%. As of December 31, 2025, none of the 2025 PSU metrics were deemed probable of achievement. The Company recorded compensation expense of $0 for the year ended December 31, 2025 related to 2025 PSUs.

The following table summarizes the activity related to performance-based restricted stock units:

As of December 31, 2025, total unrecognized compensation expense related to performance-based restricted stock units was $1,220, which amount is being recognized over a remaining weighted average period of 1.4 years.

Employee Stock Purchase Plan

In October 2020, the Company’s shareholders approved the ESPP, which became effective upon the closing of the Company’s IPO in November 2020. The Company initially reserved a total of 1,187,000 shares of its common stock for issuance under the ESPP. The ESPP provides that the number of shares reserved and available for issuance under the ESPP will be increased on January 1 of each calendar year by 1% of the number of shares of the common stock issued and outstanding on the immediately preceding December 31 or such lesser amount as specified by the board of directors. Through December 31, 2025, the number of shares of the Company's common stock available for future issuance under the ESPP was increased by 2,511,861. In January 2026, the number of shares of common stock available for future issuance under the ESPP was increased by 781,267 shares.

The Company issued 80,434 and 99,614 shares for proceeds of $201 and $267 during the years ended December 31, 2025 and 2024, respectively.

Stock-based Compensation Expense