Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation

Stock-based Compensation
6 Months Ended
Jun. 30, 2022
Share-based Payment Arrangement [Abstract]  
Stock-based Compensation Stock-based Compensation
Restricted Stock Units
Under the 2020 Equity Incentive Plan, employees are compensated through various forms of equity, including restricted stock unit awards (“RSU”). Each RSU represents a contingent right to receive one share of Common Stock. During the three and six months ended June 30, 2022, 8,932,997 and 11,743,252 RSUs were granted subject to time-based vesting.
Performance-Based Restricted Stock Units
Performance stock unit awards (“PSU”) represent the right to receive a share of Common Stock if service, performance, and market conditions, or a combination thereof, are met over a defined period. PSUs that contain a market condition, such as stock price milestones, are subject to a Monte Carlo simulation model to determine the grant date fair value by simulating a range of possible future stock prices for the Company over the performance period. The grant date fair value of the market condition PSUs is recognized as compensation expense over the greater of the Monte Carlo simulation model’s derived service period and the arrangement’s explicit service period, assuming both conditions must be met.
PSUs subject to performance conditions, such as operational milestones, are measured on the grant date, the total fair value of which is calculated as the product of the number of PSUs and the grant date stock price. Compensation expense for PSUs with a performance condition is recorded each period based upon a probability assessment of the expected outcome of the performance metric with a final adjustment upon measurement at the end of the performance period. During the three and six months ended June 30, 2022, 4,245,852 PSUs were granted to Company employees, with a total grant date fair value of approximately $13.8 million. The PSUs vest based on the Company's achievement of certain specified operational milestones by various dates through December 2025. As of the grant date, the Company's analysis determined that these operational milestone events are probable of achievement and as such, compensation expense of $1.6 million has been recognized for the three and six months ended June 30, 2022.
No PSUs were granted to the CEO during the three and six months ended June 30, 2022. The compensation expense recognized for previously awarded PSUs to the CEO was $4.4 million and $9.1 million for the three and six months ended June 30, 2022.
The following table summarizes the Company’s stock-based compensation expense by line item for the three and six months ended period presented in the condensed consolidated statements of operations (in millions):
Three months ended
June 30,
Six months ended
June 30,
2022 2021 2022 2021
Research and development $ 8.2  $ 8.5  $ 15.2  $ 15.6 
Selling, general and administrative 12.6  17.0  26.3  55.0 
Total $ 20.8  $ 25.5  $ 41.5  $ 70.6 
The Company’s total unrecognized compensation cost as of June 30, 2022, was $115.2 million.
2020 Employee Stock Purchase Plan
The 2020 Employee Stock Purchase Plan (the “2020 ESPP”) was adopted by the board of directors on September 18, 2020, approved by the stockholders on December 18, 2020, and became effective on December 21, 2020 with the Business Combination. On December 21, 2020, the board of directors delegated its authority to administer the 2020 ESPP to the Compensation Committee. The Compensation Committee determined that it is in the best interests of the Company and its stockholders to implement successive three-month purchase periods, with the first offering period commencing on grant date January 3, 2022 and a purchase date of April 1, 2022. The 2020 ESPP provides participating employees with the opportunity to purchase up to a maximum number of shares of Common Stock of 4,034,783, plus the number of shares of Common Stock that are automatically added on January 1st of each year for a period of ten years, in an amount equal to the lesser of (i) 1% of the total number of shares of Common Stock outstanding on December 31st of the preceding calendar year, and (ii) 8,069,566 shares of Common Stock.
During the three and six months ended June 30, 2022, total employee withholding contributions for the 2020 ESPP was $0.8 million and $2.0 million, respectively, a portion of which is included in restricted cash, current, within the accompanying condensed consolidated balance sheet as of June 30, 2022. Approximately $0.5 million and $0.9 million of stock-based compensation expense was recognized for the 2020 ESPP during the three and six months ended June 30, 2022, respectively.