Transaction Details

Footnotes

Restricted stock units convert into common stock on a one-for-one basis. | Includes 790 shares of Koppers Holdings Inc. common stock acquired pursuant to the Koppers Holdings Inc. Employee Stock Purchase Plan on December 31, 2024, March 31, 2025, June 30, 2025, and September 30, 2025. These acquisitions were exempt under both Rule 16b-3(c) and Rule 16b-3(d). | Represents shares acquired upon release of dividend equivalent rights ("DERs"), as reported in Table II, on a one-for-one basis. | Shares surrendered to the issuer by the reporting person as payment for the tax withholding related to the vesting of RSUs and performance share units ("PSUs"). | On January 4, 2023, the reporting person was granted PSUs for which the performance criteria for the three-year performance period from January 1, 2023 through December 31, 2025 have been satisfied. | On January 3, 2025, the reporting person was granted PSUs for which the performance criteria for the one-year performance period from January 1, 2025 through December 31, 2025 have been satisfied. All of the restricted stock units reported here are subject to vesting based on the continued service of the reporting person through January 5, 2028. If the Company's total shareholder return over the three-year period of January 1, 2025 through December 31, 2027 is negative, then the cumulative number of units that may vest for such three-year period will be capped at 150% of the target number. | The DERs accrued with respect to additional PSUs credited to the reporting person with respect to PSUs granted on January 4, 2023 and January 3, 2025. Each DER is the economic equivalent of one share of Koppers Holdings Inc. common stock. | Represents previously granted PSUs for which the performance criteria for the three-year performance period from January 1, 2023 through December 31, 2025 have been satisfied, as reported in Table II above. | These DERs were released in connection with the vesting of RSUs and PSUs granted on January 4, 2022, January 4, 2023, January 4, 2024, and January 3, 2025. Each DER is the economic equivalent of one share of Koppers Holdings Inc. common stock.