Koppers Holdings Inc. SEC filings KOP
Koppers Holdings Inc. has 1,000 filings in SEC EDGAR's recent list, going back to Jun 2, 2015. Its latest annual report, Form ARS, was filed on Mar 27, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 6, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Aug 6, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| SCHEDULE 13G | Ownership over 5% (passive) | Oct 30, 2026 | — |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | Oct 22, 2026 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Oct 19, 2026 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Oct 8, 2026 | — |
| 4 | Insider transaction | Sep 15, 2026 | Sep 14, 2026 |
| 4 | Insider transaction | Sep 15, 2026 | Sep 14, 2026 |
| 4 | Insider transaction | Sep 15, 2026 | Sep 14, 2026 |
| 4 | Insider transaction | Sep 15, 2026 | Sep 14, 2026 |
| 4 | Insider transaction | Sep 1, 2026 | Aug 31, 2026 |
| 4 | Insider transaction | Aug 20, 2026 | Aug 19, 2026 |
| 4 | Insider transaction | Aug 13, 2026 | Aug 12, 2026 |
| 4 | Insider transaction | Aug 12, 2026 | Aug 11, 2026 |
| 144 | Notice of proposed sale | Aug 12, 2026 | — |
| 4 | Insider transaction | Aug 11, 2026 | Aug 10, 2026 |
| 4 | Insider transaction | Aug 11, 2026 | Aug 7, 2026 |
| 144 | Notice of proposed sale | Aug 11, 2026 | — |
| 144 | Notice of proposed sale | Aug 10, 2026 | — |
| 144 | Notice of proposed sale | Aug 7, 2026 | — |
| 10-Q | Quarterly report | Aug 6, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Aug 6, 2026 | Aug 6, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Jul 31, 2026 | — |
| 4 | Insider transaction | Jun 23, 2026 | Jun 18, 2026 |
| 4 | Insider transaction | Jun 17, 2026 | Jun 15, 2026 |
| 4 | Insider transaction | Jun 17, 2026 | Jun 15, 2026 |
| 4 | Insider transaction | Jun 17, 2026 | Jun 15, 2026 |
| 4 | Insider transaction | Jun 17, 2026 | Jun 15, 2026 |
| 4 | Insider transaction | Jun 15, 2026 | Jun 11, 2026 |
| 4 | Insider transaction | Jun 4, 2026 | Jun 3, 2026 |
| 4 | Insider transaction | May 27, 2026 | May 26, 2026 |
| 3 | Initial insider ownership | May 27, 2026 | May 26, 2026 |
| SCHEDULE 13D | Ownership over 5% (active) | May 19, 2026 | — |
| 4 | Insider transaction | May 14, 2026 | May 12, 2026 |
| 4 | Insider transaction | May 14, 2026 | May 13, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 13, 2026 | — |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 4 | Insider transaction | May 11, 2026 | May 7, 2026 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
May 11, 2026 | May 11, 2026 |
| 10-Q | Quarterly report | May 8, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations, Exit or restructuring costs, Officer or director change, Shareholder vote results, Regulation FD disclosure
|
May 8, 2026 | May 7, 2026 |
| S-8 | Employee stock plan registration | May 8, 2026 | — |
| 8-K/A |
Amended current report
Officer or director change
|
May 7, 2026 | Nov 5, 2025 |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 30, 2026 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Apr 24, 2026 | — |
| ARS | Annual report to shareholders | Mar 27, 2026 | Dec 31, 2025 |
| DEF 14A | Proxy statement | Mar 27, 2026 | May 7, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 27, 2026 | — |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 4 | Insider transaction | Mar 25, 2026 | Mar 23, 2026 |
| 8-K/A |
Amended current report
Officer or director change
|
Mar 18, 2026 | Jan 5, 2026 |
| 4 | Insider transaction | Mar 18, 2026 | Mar 17, 2026 |
| 4 | Insider transaction | Mar 4, 2026 | Mar 2, 2026 |
| 4/A | Form 4/a | Mar 3, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2002 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Mar 2, 2026 | Feb 26, 2026 |
| 144 | Notice of proposed sale | Mar 2, 2026 | — |
| 10-K | Annual report | Feb 26, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Feb 26, 2026 | Feb 26, 2026 |
| 4 | Insider transaction | Feb 19, 2026 | Feb 18, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 8-K |
Current report
Officer or director change, Other events
|
Jan 9, 2026 | Jan 5, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Dec 17, 2025 | Dec 16, 2025 |
| 8-K/A |
Amended current report
Exit or restructuring costs
|
Dec 3, 2025 | Nov 8, 2024 |
| 4 | Insider transaction | Nov 7, 2025 | Nov 5, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Nov 5, 2025 |
| 10-Q | Quarterly report | Nov 7, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 7, 2025 | Nov 7, 2025 |
| 8-K |
Current report
Officer or director change
|
Nov 5, 2025 | Nov 5, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Oct 31, 2025 | — |
| 4 | Insider transaction | Sep 17, 2025 | Sep 15, 2025 |
| 4 | Insider transaction | Sep 17, 2025 | Sep 15, 2025 |
| 4 | Insider transaction | Sep 17, 2025 | Sep 15, 2025 |
| 4 | Insider transaction | Sep 17, 2025 | Sep 15, 2025 |
| 4 | Insider transaction | Aug 18, 2025 | Aug 15, 2025 |
| 144 | Notice of proposed sale | Aug 15, 2025 | — |
| 144 | Notice of proposed sale | Aug 11, 2025 | — |
| 10-Q | Quarterly report | Aug 8, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2025 | Aug 8, 2025 |
| 4 | Insider transaction | Jun 20, 2025 | Jun 18, 2025 |
| 8-K |
Current report
Material agreement, New debt
|
Jun 18, 2025 | Jun 17, 2025 |
| 4 | Insider transaction | Jun 16, 2025 | Jun 13, 2025 |
| 8-K |
Current report
Officer or director change, Other events
|
May 29, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 22, 2025 | May 21, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 4 | Insider transaction | May 9, 2025 | May 8, 2025 |
| 10-Q | Quarterly report | May 9, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations, Officer or director change, Shareholder vote results
|
May 9, 2025 | May 8, 2025 |
| S-8 | Employee stock plan registration | May 9, 2025 | — |
| 4 | Insider transaction | May 6, 2025 | May 2, 2025 |
| 4 | Insider transaction | May 6, 2025 | May 2, 2025 |
| 4 | Insider transaction | May 6, 2025 | May 2, 2025 |
| 4 | Insider transaction | May 6, 2025 | May 2, 2025 |
| 4 | Insider transaction | May 6, 2025 | May 2, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Apr 30, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 28, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Apr 23, 2025 | — |
| 4 | Insider transaction | Apr 14, 2025 | Apr 11, 2025 |
| DEFA14A | Additional proxy material | Apr 11, 2025 | — |
| ARS | Annual report to shareholders | Mar 28, 2025 | Dec 31, 2024 |
| DEF 14A | Proxy statement | Mar 28, 2025 | May 8, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 26, 2025 | Mar 24, 2025 |
| 4 | Insider transaction | Mar 20, 2025 | Mar 19, 2025 |
| 144 | Notice of proposed sale | Mar 19, 2025 | — |
| 4/A | Filing | Mar 11, 2025 | May 4, 2023 |
| 10-K | Annual report | Feb 27, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Feb 27, 2025 | Feb 27, 2025 |
| 3 | Initial insider ownership | Feb 24, 2025 | Feb 12, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 5, 2025 | — |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 18, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 17, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 17, 2024 | Dec 16, 2024 |
| 4 | Insider transaction | Dec 17, 2024 | Dec 16, 2024 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 17, 2024 | Dec 17, 2024 |
| 8-K |
Current report
Officer or director change
|
Dec 9, 2024 | Dec 5, 2024 |
| 8-K |
Current report
Exit or restructuring costs
|
Dec 5, 2024 | Dec 5, 2024 |
| 144 | Notice of proposed sale | Nov 22, 2024 | — |
| 4 | Insider transaction | Nov 20, 2024 | Nov 19, 2024 |
| 4 | Insider transaction | Nov 20, 2024 | Nov 19, 2024 |
| 144 | Notice of proposed sale | Nov 19, 2024 | — |
| 4 | Insider transaction | Nov 18, 2024 | Nov 14, 2024 |
| 144 | Notice of proposed sale | Nov 15, 2024 | — |
| 4 | Insider transaction | Nov 14, 2024 | Nov 12, 2024 |
| 144 | Notice of proposed sale | Nov 14, 2024 | — |
| 144 | Notice of proposed sale | Nov 13, 2024 | — |
| 4 | Insider transaction | Nov 13, 2024 | Nov 12, 2024 |
| 144 | Notice of proposed sale | Nov 12, 2024 | — |
| 144 | Notice of proposed sale | Nov 12, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Nov 8, 2024 | — |
| 10-Q | Quarterly report | Nov 8, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations, Exit or restructuring costs
|
Nov 8, 2024 | Nov 8, 2024 |
| SC 13G/A | Amended ownership over 5% (passive) | Oct 18, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Oct 7, 2024 | — |
| 4 | Insider transaction | Sep 18, 2024 | Sep 16, 2024 |
| 4 | Insider transaction | Sep 18, 2024 | Sep 16, 2024 |
| 4 | Insider transaction | Sep 18, 2024 | Sep 16, 2024 |
| 4 | Insider transaction | Aug 30, 2024 | Aug 29, 2024 |
| 144 | Notice of proposed sale | Aug 29, 2024 | — |
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Company profile
- Industry
- Lumber & Wood Products (No Furniture) (SIC 2400)
- Listed as
- KOP (NYSE)
- Fiscal year ends
- December 31
- Incorporated in
- PA
- Headquarters
- Pittsburgh, PA
- SEC filer status
- Large accelerated filer
- SEC CIK
- 1315257
- Former names
- KI Holdings Inc. (until Nov 14, 2005)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.