INCENTIVE AWARD PLAN

As of September 30, 2021, there were 4,836,249 shares available for grant as equity awards under the 2017 Incentive Award Plan. In the nine months ended September 30, 2021, the Company granted restricted stock with time-based vesting as well as performance-based awards. The performance-based awards include a market condition tied to the Company’s total shareholder return in relation to its peer companies as well as a financial performance condition tied to annual earnings per share (“EPS”) growth. The vesting and ultimate payout of performance awards is determined at the end of the three-year performance period and can vary from zero to 200% based on actual results.

The Company issued the following stock-based instruments:

A summary of the status and changes of the Company’s unvested shares is presented below:

The Company determines the fair value of restricted stock awards and any performance-related components based on the closing market price of the Company’s common stock on the date of grant. For share-based awards with a performance-based vesting requirement, the Company evaluates the probability of achieving the performance criteria throughout the performance period and will adjust stock compensation expense up or down based on its estimated probable outcome. Certain performance-based awards contain market condition components which are valued on the date of grant using a Monte Carlo simulation model.

For the three months ended September 30, 2021 and 2020, the Company recognized $14.7 million and $29.7 million of stock compensation expense. For the nine months ended September 30, 2021 and 2020, the Company recognized $41.4 million and $55.0 million of stock compensation expense. As of September 30, 2021, the unamortized stock compensation of $78.9 million is expected to be recognized over a weighted-average period of 1.87 years.

STOCK PURCHASE PLAN

A total of 5,000,000 shares of Class A Common Stock are available for sale under the 2018 Employee Stock Purchase Plan (“2018 ESPP”). The 2018 ESPP provides eligible employees of the Company and its subsidiaries the opportunity to purchase shares of the Company’s Class A Common Stock at a purchase price equal to 85% of the fair market value on the first trading day or last trading day of each purchase period, whichever is lower. Eligible employees can invest up to 15% of their compensation through payroll deductions during each purchase period. The purchase price discount and the look-back feature cause the 2018 ESPP to be compensatory and the Company recognizes compensation expense, which is computed using the Black-Scholes valuation model.