In April 2021, the Company’s board of directors adopted, and in May 2021 its stockholders approved the 2021 Equity Incentive Plan (the 2021 Plan).

No further awards are being made under the Company’s 2009 Equity Incentive Plan, as amended (the 2009 Plan) or the Company’s 2018 Stock Incentive Plan (the 2018 Plan); however, awards outstanding under each of the 2009 Plan and 2018 Plan will continue to be governed by their existing terms. With the establishment of the 2021 Plan as further discussed below, upon the expiration, forfeiture, cancellation, or reacquisition of any stock-based awards granted under the 2009 Plan or 2018 Plan, an equal number of shares will become available for grant under the 2021 Plan. The 2021 Plan, 2018 Plan and 2009 Plan are collectively referred to as the “Equity Incentive Plans”.

The 2021 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards and other forms of equity compensation (collectively, equity awards). A total of 26,116,754 shares of the Company’s common stock have been reserved for issuance under the 2021 Plan in addition to (i) any annual automatic evergreen increases in the number of shares of common stock reserved for issuance under the 2021 Plan and (ii) upon the expiration, forfeiture, cancellation, or reacquisition of any stock-based awards granted under the 2009 Plan or 2018 Plan, an equal number of shares of common stock will become available under the 2021 Plan.

As of June 30, 2024, a total of 17,725,359 shares of the Company's common stock were available for future issuance under the 2021 Plan.

Stock options granted under the 2009 Plan, 2018 Plan and the 2021 Plan generally vest based on continued service over four years and expire within ten years from the date of grant. Any options that are canceled or forfeited before expiration become available for future grants.

The Company did not grant any options to purchase shares of common stock during the three and six months ended June 30, 2024.

As of June 30, 2024, there was $6.4 million of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 0.96 years.

Starting in 2021, the Company awarded restricted stock units to employees and certain non-employee board members under the 2021 Plan. During the three and six months ended June 30, 2024, the Company awarded restricted stock units covering an aggregate of 130,608 and 3,297,377 shares of common stock, respectively. The fair value of each restricted stock unit is estimated based on the fair value of the Company's common stock on the date of the grant. The restricted stock units vest over the requisite service period, which range between one and four years from the date of the grant, subject to the continued employment of the employees and service of the non-employee board members.

As of June 30, 2024, there was $142.7 million of total unrecognized compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted-average period of 3.11 years.

In April 2021, the Company’s board of directors adopted, and in May 2021 its stockholders approved, the 2021 Employee Stock Purchase Plan (ESPP), which became effective on May 28, 2021. The ESPP authorizes the issuance of shares of common stock pursuant to purchase rights granted to "eligible employees". A total of 5,082,470 shares of common stock have been reserved for future issuance under the ESPP, in addition to any annual automatic evergreen increases in the number of shares of common stock reserved for future issuance under the ESPP. The price at which common stock is purchased under the ESPP is equal to 85% of the fair market value of a share of common stock on the first or last day of the offering period, whichever is lower. Eligible employees can contribute up to 15% of their eligible compensation. Offering periods are generally 6 months long.

As of June 30, 2024, a total of 4,720,458 shares of the Company's common stock were available for future issuance under the ESPP.

As of June 30, 2024, there was no unrecognized compensation expense related to the ESPP.

The following table summarizes the stock-based compensation expense for (i) stock options and restricted stock units granted to employees and non-employee board members and (ii) ESPP shares that were purchased by employees that were recorded in the Company’s condensed consolidated statements of operations and comprehensive loss (in thousands):


	Three Months Ended June 30, 2024		Three Months Ended June 30, 2023		Six Months Ended June 30, 2024		Six Months Ended June 30, 2023
Technology and development	$	2,830	$	2,399	$	5,422	$	3,968
Selling and marketing		4,660		3,294		8,620		5,731
General and administrative		9,571		5,683		17,861		10,280
Total stock-based compensation expense	$	17,061	$	11,376	$	31,903	$	19,979

On November 6, 2023, the Company entered into a Transition Agreement with its previous Chief Financial Officer (Prior CFO). Pursuant to the terms of the Transition Agreement (including the receipt by the Company of a release from the Prior CFO), the Company agreed to modify its Prior CFO's outstanding stock options and restricted stock units to (i) accelerate vesting for nine months from the date of the termination of the Prior CFOs employment with the Company (the Separation Date), and (ii) extend the exercise period of his vested nonqualified stock options from ninety days to one year following the Separation Date. To receive these benefits, the Prior CFO had to remain employed through March 31, 2024. As a result of this modification, the Company recognized additional compensation expense of $1.3 million during the three and six months ended June 30, 2024.