| Date Filed | Type | Description |
| 10/12/2023 |
8-K
| Quarterly results |
| 08/07/2023 |
144
| Form 144 - Report of proposed sale of securities: |
| 08/03/2023 |
8-K
| Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits ... |
| 08/03/2023 |
10-Q
| Quarterly Report for the period ended June 30, 2023 |
| 08/03/2023 |
8-K
| Quarterly results |
| 08/01/2023 |
144
| Form 144 - Report of proposed sale of securities: |
| 06/06/2023 |
144
| Form 144 - Report of proposed sale of securities: |
| 05/05/2023 |
10-Q
| Quarterly Report for the period ended March 31, 2023 |
| 05/05/2023 |
8-K
| Quarterly results |
| 05/04/2023 |
8-K/A
| Quarterly results |
| 04/03/2023 |
ARS
| Form ARS - Annual Report to Security Holders: |
| 04/03/2023 |
DEF 14A
| Form DEF 14A - Other definitive proxy statements: |
| 03/22/2023 |
8-K
| Appointed a new director |
| 03/10/2023 |
8-K
| Other Events, Financial Statements and Exhibits Interactive Data |
| 02/27/2023 |
10-K
| Annual Report for the period ended December 31, 2022 |
| 02/27/2023 |
8-K
| Results of Operations and Financial Condition, Financial Statements and Exhibits Interactive Data |
| 02/14/2023 |
SC 13G/A
| FULLER & THALER ASSET MANAGEMENT, INC. reports a 10.6% stake in Koppers Holdings Inc. |
| 01/20/2023 |
SC 13G
| BlackRock Inc. reports a 16.8% stake in KOPPERS HOLDINGS INC |
| 01/20/2023 |
5
| Hyde Leslie S (SVP, Chief Sustainability Offi) has filed a Form 5 on Koppers Holdings Inc. |
| 01/20/2023 |
5
| BALL M LEROY (President and CEO) has filed a Form 5 on Koppers Holdings Inc. |
| 12/13/2022 |
8-K
| Quarterly results |
| 11/04/2022 |
10-Q
| Quarterly Report for the period ended September 30, 2022 |
| 11/04/2022 |
8-K
| Quarterly results |
| 08/04/2022 |
10-Q
| Quarterly Report for the period ended June 30, 2022 |
| 08/04/2022 |
8-K
| Quarterly results |
| 06/21/2022 |
8-K
| Quarterly results |
| 05/06/2022 |
10-Q
| Quarterly Report for the period ended March 31, 2022 |
| 05/06/2022 |
8-K
| Quarterly results |
| 04/04/2022 |
DEF 14A
| Form DEF 14A - Other definitive proxy statements: |
| 03/02/2022 |
SC 13G/A
| FULLER & THALER ASSET MANAGEMENT, INC. reports a 10.1% stake in Koppers Holdings Inc. |
| 02/23/2022 |
10-K
| Annual Report for the period ended December 31, 2021 |
| 02/23/2022 |
8-K
| Quarterly results |
| 02/14/2022 |
SC 13G
| Rubric Capital Management LP reports a 5.2% stake in Koppers Holdings Inc. |
| 02/10/2022 |
SC 13G/A
| VANGUARD GROUP INC reports a 11.1% stake in Koppers Holdings Inc. |
|