11. Stock-based Compensation

The total number of shares of common stock authorized for issuance under the 2025 Equity Incentive Plan (the 2025 Plan) upon its adoption in May 2025 was 5,500,000. The number of shares authorized for issuance under the 2025 Plan shall automatically increase for any shares of common stock underlying awards outstanding under the 2015 Equity Incentive Plan (the 2015 Plan), as of the adoption date of the 2025 Plan, which are not issued due to forfeiture, expiration, termination or cancellation of the award including, subject to shareholder approval at the 2026 Annual Meeting of Stockholders, an exchange of the award (to the extent that surrendered options exceed newly issued options in such exchange). Shares of common stock that are withheld, tendered, or otherwise not issued in connection with the settlement of awards outstanding under the 2015 Plan do not increase the number of shares authorized for issuance under the 2025 Plan. As of June 30, 2026, the total number of shares of common stock reserved for issuance under the 2025 Plan and 2015 Plan was 18,957,280, of which 3,826,446 remained available for future grants under the 2025 Plan.

The Company's equity incentive plans provide for the issuance of stock options, stock appreciation rights, restricted and unrestricted stock and unit awards, and performance cash awards to employees, members of the Board of Directors and consultants of the Company. As of June 30, 2026, the Company has issued only stock options, restricted stock units (RSUs) and performance stock units (PSUs) under its equity plans. Stock options generally expire 10 years following the date of grant and typically vest over a four-year service period, but contractual terms and vesting provisions can vary by award based on the discretion of the Board of Directors. Stock options have an exercise price at least equal to the estimated fair value of the Company’s common stock on the date of grant. RSUs typically vest over a four-year service period, but vesting provisions can vary by award based on the discretion of the Board of Directors. In January 2026, the Company granted PSUs to certain executive employees. PSUs have similar terms and conditions as RSUs, except that vesting is contingent upon the achievement of specified performance conditions in addition to service conditions over a period of one year. Upon vesting, RSUs and PSUs are settled in common stock of the Company. Awards granted under the 2025 Plan generally have a minimum vesting requirement of one year from the grant date.

Stock-based Compensation Expense

As of June 30, 2026, the Company had $53.2 million of unrecognized stock-based compensation expense related to stock options, RSUs, PSUs and the 2015 Employee Stock Purchase Plan (the 2015 ESPP), which is expected to be recognized over a weighted-average period of 2.4 years.

Stock Options

The weighted-average grant date fair value per share of options granted during the six months ended June 30, 2026 was $6.94. During the six months ended June 30, 2026, the total number of stock options exercised was 247,717, resulting in total proceeds of $0.2 million. The number of stock options exercised during the period includes shares withheld to cover option cost and taxes. The total intrinsic value of options exercised during the six months ended June 30, 2026 was $0.1 million.

Stock Option Exchange Program

On June 3, 2026, the Company commenced an offer to exchange (the Offer to Exchange) certain eligible stock options held by eligible non-executive employees for replacement stock options under a voluntary stock option exchange program (the Stock Option Exchange Program).

Under the Stock Option Exchange Program, eligible employees were offered the opportunity to exchange outstanding stock options granted under the 2015 Plan that have an exercise price equal to or greater than $18.00 per share (Eligible Options), for a lesser number of replacement stock options to be granted under the 2025 Plan with an exercise price per share equal to the fair value of the Company’s common stock on the replacement option grant date (Replacement Options). The number of Replacement Options granted in exchange for Eligible Options surrendered shall be calculated based on specified exchange ratios which vary based on the grant date and exercise price of the Eligible Options. The exchange ratios were established in order to result in a fair value of the Replacement Options that was generally equal, on an aggregate basis, to the fair value of the Eligible Options surrendered.

The Offer to Exchange expired on July 1, 2026. Pursuant to the terms and conditions of the Offer to Exchange, a total of 184 eligible employees elected to exchange a total of 1,940,394 Eligible Options with a weighted-average exercise price of $35.13 per share, representing approximately 67.0% of the total Eligible Options outstanding. On July 2, 2026, all Eligible Options that were tendered were cancelled and, in exchange therefore, the Company granted Replacement Options to purchase 775,401 shares of common stock with an exercise price of $13.28 per share, which was the closing price of the Company's common stock on July 2, 2026. The Replacement Options expire eight years from the grant date and are subject to new vesting schedules based on continued service over a period of two years from the grant date. Effective July 2, 2026, a total of 1,164,933 shares of common stock were added to the number of shares available for future grants under the 2025 Plan, which represents the total number of Eligible Options cancelled, less of the total number of Replacement Options granted, under the Stock Option Exchange Program.

The exchange of Eligible Options for Replacement Options under the Stock Option Exchange Program is expected to be accounted for as a modification of the Eligible Options in the third quarter of 2026. Since the Stock Option Program was designed as a value-for-value exchange, the Company does not expect the incremental stock-based compensation resulting from the modification of the awards to be material to the Company's consolidated financial statements. Any such incremental stock-based compensation resulting from the Stock Option Exchange will be recognized over the two-year vesting period of the Replacement Options.

Restricted Stock Units

The total intrinsic value of RSUs vested during the six months ended June 30, 2026 was $11.2 million.

Performance Stock Units

In January 2026, the Company granted PSUs to certain executive employees. Vesting of the PSUs is contingent upon the achievement of specified performance conditions pre-determined by the Board of Directors, as well as service conditions over a requisite service period. The performance conditions are based on certain specified business objectives and are non-market based. As determined by the Board of Directors, each performance condition that is achieved during the applicable performance period will result in the vesting of a specified number of PSUs one year from the grant date, subject to the grantee's continued service through the vesting date.

Stock-based compensation expense for PSUs is measured based on the grant date fair value of the award, which is determined based on the fair value of the Company's stock on the grant date, and is recognized over the requisite service period beginning in the period it is probable that the performance conditions will be achieved. As of June 30, 2026, certain specified performance conditions were achieved or deemed probable of achievement but vesting of the associated PSUs remains subject to continued service conditions. No PSUs vested during the six months ended June 30, 2026.

Employee Stock Purchase Plan

As of June 30, 2026, the total number of shares of common stock authorized for issuance under the 2015 ESPP was 1,426,994, of which 662,624 remained available for future issuance. During the six months ended June 30, 2026, 92,682 shares of common stock were issued under the 2015 ESPP.