Koppers Holdings Inc. — All Filings
1,004 total filings on record
Public companies registered with the SEC are required to file periodic reports, disclosures, and notices throughout the year. The most important are the 10-K (annual report), 10-Q (quarterly report), and 8-K (material event notice). Use the filters below to narrow by form type.
All
10-K
10-K/A
10-Q
144
144/A
3
3/A
4
4/A
424B1
424B3
5
5/A
8-A12B
8-K
8-K/A
ARS
CERTNYS
CORRESP
DEF 14A
DEFA14A
EFFECT
POS AM
POSASR
PRE 14A
S-1
S-1/A
S-3
S-3/A
S-3ASR
S-4
S-4/A
S-8
SC 13G
SC 13G/A
SCHEDULE 13G
SCHEDULE 13G/A
UPLOAD
| Form | Description | Accession Number | Filed | Period |
|---|---|---|---|---|
| DEF 14A | DEF 14A | 0001315257-26-000026 | Mar 27, 2026 | May 7, 2026 |
| SCHEDULE 13G/A | — | 0000102909-26-001632 | Mar 27, 2026 | — |
| ARS | ARS | 0001315257-26-000027 | Mar 27, 2026 | Dec 31, 2025 |
| 4 | FORM 4 | 0002092070-26-000002 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001315257-26-000024 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001584601-26-000004 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001190210-26-000002 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001533627-26-000002 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001315257-26-000022 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001739998-26-000002 | Mar 25, 2026 | Mar 23, 2026 |
| 4 | FORM 4 | 0001564614-26-000002 | Mar 25, 2026 | Mar 23, 2026 |
| 8-K/A | 8-K/A | 0001315257-26-000017 | Mar 18, 2026 | Jan 5, 2026 |
| 4 | FORM 4 | 0001229771-26-000008 | Mar 18, 2026 | Mar 17, 2026 |
| 4 | FORM 4 | 0001229771-26-000006 | Mar 4, 2026 | Mar 2, 2026 |
| 4/A | FORM 4/A | 0001919175-26-000006 | Mar 3, 2026 | Feb 26, 2026 |
| 144 | — | 0001959173-26-001645 | Mar 2, 2026 | — |
| 4 | FORM 4 | 0001315257-26-000014 | Mar 2, 2026 | Feb 26, 2026 |
| 4 | FORM 4 | 0001776180-26-000004 | Mar 2, 2026 | Feb 26, 2026 |
| 4 | FORM 4 | 0001919175-26-000004 | Mar 2, 2026 | Feb 26, 2002 |
| 4 | FORM 4 | 0002057699-26-000004 | Mar 2, 2026 | Feb 26, 2026 |
| 4 | FORM 4 | 0001229771-26-000004 | Mar 2, 2026 | Feb 26, 2026 |
| 4 | FORM 4 | 0001450800-26-000004 | Mar 2, 2026 | Feb 26, 2026 |
| 10-K | 10-K | 0001315257-26-000012 | Feb 26, 2026 | Dec 31, 2025 |
| 8-K | 8-K | 0001315257-26-000010 | Feb 26, 2026 | — |
| 4 | FORM 4 | 0001229771-26-000002 | Feb 19, 2026 | Feb 18, 2026 |
| 4 | FORM 4 | 0001315257-26-000006 | Feb 12, 2026 | Feb 10, 2026 |
| 8-K | 8-K | 0001315257-26-000004 | Jan 9, 2026 | Jan 5, 2026 |
| 4 | FORM 4 | 0002057699-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001919175-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001684691-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001450800-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001315257-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001776180-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001806249-26-000002 | Jan 6, 2026 | Jan 2, 2026 |
| 4 | FORM 4 | 0001776180-25-000003 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001315257-25-000015 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001806249-25-000003 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001584601-25-000006 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001684691-25-000005 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001229771-25-000003 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001919175-25-000003 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001739998-25-000007 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0002057699-25-000003 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001450800-25-000004 | Dec 17, 2025 | Dec 16, 2025 |
| 4 | FORM 4 | 0001463649-25-000005 | Dec 17, 2025 | Dec 16, 2025 |
| 8-K/A | 8-K | 0001315257-25-000014 | Dec 3, 2025 | Nov 8, 2024 |
| 8-K | 8-K | 0001315257-25-000010 | Nov 7, 2025 | — |
| 10-Q | 10-Q | 0001315257-25-000012 | Nov 7, 2025 | Sep 30, 2025 |
| 3 | FORM 3 | 0002092070-25-000002 | Nov 7, 2025 | Nov 5, 2025 |
| 4 | FORM 4 | 0002092070-25-000004 | Nov 7, 2025 | Nov 5, 2025 |