Covista Inc.

15. Stock-Based Compensation

Under Covista’s current stock-based incentive plan, employees and Board members are eligible to receive stock options, restricted stock units (“RSUs”), performance-based restricted stock units (“PSUs”), and other forms of stock awards. As of September 30, 2026,1,049,997 shares of common stock were available for future issuance under this plan.

Stock-based compensation expense is recognized on a straight-line basis over the requisite service period. We account for forfeitures of unvested awards in the period they occur. Covista issues new shares of common stock to satisfy stock option exercises, RSU vests, and PSU vests. Stock-based compensation expense is included in student services and administrative expense in the Consolidated Statements of Income. There wasno capitalized stock-based compensation cost as of September 30, 2026 and June 30, 2026.

Stock Options

Beginning in fiscal year 2023, the Compensation Committee of the Board determined to no longer grant stock options. Prior to fiscal year 2023, we granted stock options generally with afour-year graded vesting from the grant date that expireten years from the grant date. The following table summarizes stock option activity for the three months ended September 30, 2026:

As of June 30, 2026, all stock options were vested. Therefore, no stock options vested during the three months ended September 30, 2026 and there isno remaining unrecognized stock-based compensation expense related to unvested stock options as of September 30, 2026. The fair value of stock options that vested during the three months ended September 30, 2025 was $0.6 million. The total intrinsic value of stock options exercised for the three months ended September 30, 2025 was $0.4 million. There wereno stock options exercised during the three months ended September 30, 2026.

RSUs

We grant RSUs generally with athree-year graded vesting from the grant date. We also grant RSUs to our Board members with aone-year cliff vest from the grant date. The fair value per share of RSUs is the closing market price of our common stock on the grant date. The following table summarizes RSU activity for the three months ended September 30, 2026:

The weighted-average grant date fair value per share of RSUs granted in the three months ended September 30, 2026 and 2025 was $116.41 and $117.85, respectively. The grant date fair value of RSUs that vested during the three months

ended September 30, 2026 and 2025 was $3.1 million and $8.9 million, respectively. As of September 30, 2026, $10.0 million of unrecognized stock-based compensation expense related to unvested RSUs is expected to be recognized over a remaining weighted-average period of 1.6 years.

PSUs

We grant PSUs with an approximate three-year cliff vest from the grant date. The fair value per share of PSUs is the closing market price of our common stock on the grant date. We estimate the number of shares that will vest under our PSU awards when recognizing stock-based compensation expense for each reporting period. The final number of shares that vest under our PSUs is based on metrics approved by the Compensation Committee of the Board. The following table summarizes PSU activity for the three months ended September 30, 2026:

The grant date fair value of PSUs that vested during the three months ended September 30, 2026 and 2025 was $13.4 million and $20.4 million, respectively. As of September 30, 2026, $14.1 million of unrecognized stock-based compensation expense related to unvested PSUs is expected to be recognized over a remaining weighted-average period of 0.9 years.