# Koppers Holdings Inc.: filings

KOP · NYSE · CIK 1315257 · [Materials](/sectors/materials.md) · fiscal year ends Dec 31

Pages: [Overview](/companies/kop.md) · [Financials](/companies/kop/financials.md) · [Filings](/companies/kop/filings.md) · [Insiders](/companies/kop/insiders.md)

## Reports and events: 257 filings

Newest first, by EDGAR acceptance time (Eastern). Filter with ?form= one of: `periodic`, `8-K`, `10-K`, `10-Q`, `4`, `proxy`, `13dg`, `all`, or any form this company filed (4 1082, 8-K 156, SC 13G/A 71, 4/A 65, 144 58, 10-Q 53, 3 32, SC 13G 27, 5 21, 10-K 18, DEF 14A 18, ARS 11, CORRESP 11, UPLOAD 11, S-8 10, 8-K/A 9, SCHEDULE 13G/A 7, 3/A 4, DEFA14A 4, 424B3 3, EFFECT 3, PRE 14A 3, S-3ASR 3, SCHEDULE 13G 3, 5/A 2, S-3/A 2, S-4/A 2, 10-K/A 1, 144/A 1, POS AM 1, POSASR 1, S-3 1, S-4 1, SCHEDULE 13D 1, SCHEDULE 13D/A 1).

| Filed | Accepted | Form | What it is | Accession |
| --- | --- | --- | --- | --- |
| 2026-10-22 | 18:28 ET | [SCHEDULE 13D/A](/filings/0000921895-26-002844.md) | Ownership report, active investor, amended | 0000921895-26-002844 |
| 2026-08-06 | 12:05 ET | [10-Q](/filings/0001315257-26-000048.md) | Quarterly report, period 2026-06-30 | 0001315257-26-000048 |
| 2026-08-06 | 08:14 ET | [8-K](/filings/0001315257-26-000046.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0001315257-26-000046 |
| 2026-05-19 | 17:33 ET | [SCHEDULE 13D](/filings/0000921895-26-001441.md) | Ownership report, active investor | 0000921895-26-001441 |
| 2026-05-11 | 09:05 ET | [8-K](/filings/0001315257-26-000041.md) | 5.02 Departure or appointment of officers or directors; 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0001315257-26-000041 |
| 2026-05-08 | 12:05 ET | [10-Q](/filings/0001315257-26-000038.md) | Quarterly report, period 2026-03-31 | 0001315257-26-000038 |
| 2026-05-08 | 09:10 ET | [8-K](/filings/0001315257-26-000036.md) | 2.02 Results of operations; 2.05 Exit or disposal costs; 5.02 Departure or appointment of officers or directors; 5.07 Shareholder vote results; 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0001315257-26-000036 |
| 2026-05-07 | 16:18 ET | [8-K/A](/filings/0001315257-26-000030.md) | 5.02 Departure or appointment of officers or directors; 9.01 Financial statements and exhibits | 0001315257-26-000030 |
| 2026-03-27 | 16:30 ET | [DEF 14A](/filings/0001315257-26-000026.md) | Proxy statement, period 2026-05-07 | 0001315257-26-000026 |
| 2026-03-18 | 16:45 ET | [8-K/A](/filings/0001315257-26-000017.md) | 5.02 Departure or appointment of officers or directors; 9.01 Financial statements and exhibits | 0001315257-26-000017 |
| 2026-02-26 | 12:17 ET | [10-K](/filings/0001315257-26-000012.md) | Annual report, period 2025-12-31 | 0001315257-26-000012 |
| 2026-02-26 | 08:59 ET | [8-K](/filings/0001315257-26-000010.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0001315257-26-000010 |
| 2026-01-09 | 08:15 ET | [8-K](/filings/0001315257-26-000004.md) | 5.02 Departure or appointment of officers or directors; 8.01 Other events; 9.01 Financial statements and exhibits | 0001315257-26-000004 |
| 2025-12-03 | 16:35 ET | [8-K/A](/filings/0001315257-25-000014.md) | 2.05 Exit or disposal costs | 0001315257-25-000014 |
| 2025-11-07 | 12:37 ET | [10-Q](/filings/0001315257-25-000012.md) | Quarterly report, period 2025-09-30 | 0001315257-25-000012 |
| 2025-11-07 | 08:22 ET | [8-K](/filings/0001315257-25-000010.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0001315257-25-000010 |
| 2025-11-05 | 16:35 ET | [8-K](/filings/0001315257-25-000006.md) | 5.02 Departure or appointment of officers or directors; 9.01 Financial statements and exhibits | 0001315257-25-000006 |
| 2025-08-08 | 11:59 ET | [10-Q](/filings/0000950170-25-105595.md) | Quarterly report, period 2025-06-30 | 0000950170-25-105595 |
| 2025-08-08 | 08:10 ET | [8-K](/filings/0000950170-25-105486.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-25-105486 |
| 2025-06-18 | 08:01 ET | [8-K](/filings/0000950170-25-087681.md) | 1.01 Entry into a material agreement; 2.03 New direct financial obligation; 9.01 Financial statements and exhibits | 0000950170-25-087681 |
| 2025-05-29 | 08:00 ET | [8-K](/filings/0000950170-25-078597.md) | 5.02 Departure or appointment of officers or directors; 8.01 Other events; 9.01 Financial statements and exhibits | 0000950170-25-078597 |
| 2025-05-09 | 12:21 ET | [10-Q](/filings/0000950170-25-067733.md) | Quarterly report, period 2025-03-31 | 0000950170-25-067733 |
| 2025-05-09 | 08:19 ET | [8-K](/filings/0000950170-25-067521.md) | 2.02 Results of operations; 5.02 Departure or appointment of officers or directors; 5.07 Shareholder vote results; 9.01 Financial statements and exhibits | 0000950170-25-067521 |
| 2025-03-28 | 16:30 ET | [DEF 14A](/filings/0000950170-25-046841.md) | Proxy statement, period 2025-05-08 | 0000950170-25-046841 |
| 2025-02-27 | 11:53 ET | [10-K](/filings/0000950170-25-028542.md) | Annual report, period 2024-12-31 | 0000950170-25-028542 |
| 2025-02-27 | 08:33 ET | [8-K](/filings/0000950170-25-028398.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-25-028398 |
| 2024-12-17 | 16:31 ET | [8-K](/filings/0001193125-24-280510.md) | 1.01 Entry into a material agreement; 2.03 New direct financial obligation; 9.01 Financial statements and exhibits | 0001193125-24-280510 |
| 2024-12-09 | 07:58 ET | [8-K](/filings/0000950170-24-134339.md) | 5.02 Departure or appointment of officers or directors | 0000950170-24-134339 |
| 2024-12-05 | 16:45 ET | [8-K](/filings/0000950170-24-133737.md) | 2.05 Exit or disposal costs; 9.01 Financial statements and exhibits | 0000950170-24-133737 |
| 2024-11-08 | 11:59 ET | [10-Q](/filings/0000950170-24-123804.md) | Quarterly report, period 2024-09-30 | 0000950170-24-123804 |
| 2024-11-08 | 08:24 ET | [8-K](/filings/0000950170-24-123708.md) | 2.02 Results of operations; 2.05 Exit or disposal costs; 9.01 Financial statements and exhibits | 0000950170-24-123708 |
| 2024-08-08 | 12:16 ET | [10-Q](/filings/0000950170-24-093561.md) | Quarterly report, period 2024-06-30 | 0000950170-24-093561 |
| 2024-08-08 | 08:24 ET | [8-K](/filings/0000950170-24-093360.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-24-093360 |
| 2024-05-03 | 14:01 ET | [10-Q](/filings/0000950170-24-052678.md) | Quarterly report, period 2024-03-31 | 0000950170-24-052678 |
| 2024-05-03 | 08:26 ET | [8-K](/filings/0000950170-24-052494.md) | 2.02 Results of operations; 5.03 Amendment to articles or bylaws; 5.07 Shareholder vote results; 9.01 Financial statements and exhibits | 0000950170-24-052494 |
| 2024-05-02 | 16:15 ET | [8-K/A](/filings/0000950170-24-052134.md) | 5.02 Departure or appointment of officers or directors; 9.01 Financial statements and exhibits | 0000950170-24-052134 |
| 2024-04-15 | 08:06 ET | [8-K](/filings/0001193125-24-095544.md) | 1.01 Entry into a material agreement; 2.03 New direct financial obligation; 9.01 Financial statements and exhibits | 0001193125-24-095544 |
| 2024-04-02 | 16:34 ET | [DEF 14A](/filings/0001193125-24-084813.md) | Proxy statement, period 2024-05-02 | 0001193125-24-084813 |
| 2024-02-28 | 12:09 ET | [10-K](/filings/0000950170-24-021787.md) | Annual report, period 2023-12-31 | 0000950170-24-021787 |
| 2024-02-28 | 08:17 ET | [8-K](/filings/0000950170-24-021675.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-24-021675 |
| 2024-02-13 | 16:30 ET | [8-K](/filings/0000950170-24-014607.md) | 5.02 Departure or appointment of officers or directors; 9.01 Financial statements and exhibits | 0000950170-24-014607 |
| 2024-01-02 | 16:30 ET | [8-K](/filings/0000950170-24-000286.md) | 5.02 Departure or appointment of officers or directors; 8.01 Other events; 9.01 Financial statements and exhibits | 0000950170-24-000286 |
| 2023-11-03 | 12:25 ET | [10-Q](/filings/0000950170-23-058640.md) | Quarterly report, period 2023-09-30 | 0000950170-23-058640 |
| 2023-11-03 | 08:21 ET | [8-K](/filings/0000950170-23-058530.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-23-058530 |
| 2023-10-12 | 08:46 ET | [8-K](/filings/0001193125-23-254683.md) | 1.01 Entry into a material agreement; 2.03 New direct financial obligation; 9.01 Financial statements and exhibits | 0001193125-23-254683 |
| 2023-09-14 | 08:32 ET | [8-K](/filings/0000950170-23-048041.md) | 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0000950170-23-048041 |
| 2023-08-03 | 16:34 ET | [8-K](/filings/0000950170-23-038090.md) | 5.03 Amendment to articles or bylaws; 9.01 Financial statements and exhibits | 0000950170-23-038090 |
| 2023-08-03 | 12:07 ET | [10-Q](/filings/0000950170-23-037727.md) | Quarterly report, period 2023-06-30 | 0000950170-23-037727 |
| 2023-08-03 | 08:27 ET | [8-K](/filings/0000950170-23-037613.md) | 2.02 Results of operations; 9.01 Financial statements and exhibits | 0000950170-23-037613 |
| 2023-05-05 | 11:55 ET | [10-Q](/filings/0000950170-23-018172.md) | Quarterly report, period 2023-03-31 | 0000950170-23-018172 |

Page 1 of 6. [Older](/companies/kop/filings.md?page=2)
Source: SEC EDGAR, the company’s filing index. Last ingested by Listed: Oct 30, 2026, 12:04 ET. No prices; not investment advice.