Koppers Holdings Inc. SEC filings

Filings

1. SCHEDULE 13G/AKoppers Holdings Inc.KOPOct 8

   Koppers Holdings Inc

   • Dimensional Fund Advisors LP filed Schedule 13G/A on 2026-10-08.
   • Owns 1,265,529 shares (6.7% of class).
   • Sole voting power: 1,240,909 shares.

   DIMENSIONAL FUND ADVISORS LP, filed by

2. 4Koppers Holdings Inc.KOPSep 15

   4 insider filings

   Sonja Michelle Wilkerson, insider filing for KOP

   Show all 4

   • 4Insider filing for KOPSep 15
   • 4Insider filing for KOPSep 15
   • 4Insider filing for KOPSep 15
   • 4Insider filing for KOPSep 15

   Sonja Michelle Wilkerson, reporting

3. 4Koppers Holdings Inc.KOPSep 1

   M Leroy Ball, insider filing for KOP

   M Leroy Ball, reporting

4. 4Koppers Holdings Inc.KOPAug 20

   M Leroy Ball, insider filing for KOP

   M Leroy Ball, reporting

5. 4Koppers Holdings Inc.KOPAug 13

   Stephen G Lucas, insider filing for KOP

   Stephen G Lucas, reporting

6. 4Koppers Holdings Inc.KOPAug 12

   James A. Sullivan, insider filing for KOP

   James A. Sullivan, reporting

7. 144Koppers Holdings Inc.KOPAug 12

   Stephen G Lucas, planned sale of KOP shares

   Stephen G Lucas, reporting

8. 4Koppers Holdings Inc.KOPAug 11

   2 insider filings

   Bradley A Pearce, insider filing for KOP

   Show all 2

   • 4Insider filing for KOPAug 11
   • 4Insider filing for KOPAug 11

   Bradley A Pearce, reporting

9. 144Koppers Holdings Inc.KOPAug 11

   James A. Sullivan, planned sale of KOP shares

   James A. Sullivan, reporting

10. 144Koppers Holdings Inc.KOPAug 10

    Bradley A Pearce, planned sale of KOP shares

    Bradley A Pearce, reporting

11. 144Koppers Holdings Inc.KOPAug 7

    James A. Sullivan, planned sale of KOP shares

    James A. Sullivan, reporting

12. 10-QKoppers Holdings Inc.KOPAug 6

    Quarterly report

13. 8-KKoppers Holdings Inc.KOPAug 6

    Current report

14. SCHEDULE 13G/AKoppers Holdings Inc.KOPJul 31

    Ownership stake disclosure by VANGUARD CAPITAL MANAGEMENT LLC (amended)

    VANGUARD CAPITAL MANAGEMENT LLC, filed by

15. 4Koppers Holdings Inc.KOPJun 23

    M Leroy Ball, insider filing for KOP

    M Leroy Ball, reporting

16. 4Koppers Holdings Inc.KOPJun 17

    4 insider filings

    Sonja Michelle Wilkerson, insider filing for KOP

    Show all 4

    • 4Insider filing for KOPJun 17
    • 4Insider filing for KOPJun 17
    • 4Insider filing for KOPJun 17
    • 4Insider filing for KOPJun 17

    Sonja Michelle Wilkerson, reporting

17. 4Koppers Holdings Inc.KOPJun 15

    M Leroy Ball, insider filing for KOP

    M Leroy Ball, reporting

18. 4Koppers Holdings Inc.KOPJun 4

    Xudong Feng, insider filing for KOP

    Xudong Feng, reporting

19. 4Koppers Holdings Inc.KOPMay 27

    2 insider filings

    Eric D. Brenner, insider filing for KOP

    Show all 2

    • 4Insider filing for KOPMay 27
    • 3New insider at KOPMay 27

    Eric D. Brenner, reporting

20. SCHEDULE 13DKoppers Holdings Inc.KOPMay 19

    Ownership stake disclosure by Simcoe Capital Management, LLC

    Simcoe Capital Management, LLC, filed by

21. 4Koppers Holdings Inc.KOPMay 14

    2 insider filings

    Bradley A Pearce, insider filing for KOP

    Show all 2

    • 4Insider filing for KOPMay 14
    • 4Insider filing for KOPMay 14

    Bradley A Pearce, reporting

22. SCHEDULE 13G/AKoppers Holdings Inc.KOPMay 13

    Ownership stake disclosure by FULLER & THALER ASSET MANAGEMENT, INC. (amended)

    FULLER & THALER ASSET MANAGEMENT, INC., filed by

23. 4Koppers Holdings Inc.KOPMay 11

    8 insider filings

    David L Motley, insider filing for KOP

    Show all 8

    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11
    • 4Insider filing for KOPMay 11

    David L Motley, reporting

24. 8-KKoppers Holdings Inc.KOPMay 11

    Current report

25. 10-QKoppers Holdings Inc.KOPMay 8

    Quarterly report

26. 8-KKoppers Holdings Inc.KOPMay 8

    Current report

27. S-8Koppers Holdings Inc.KOPMay 8

    Employee stock plan registration

28. 8-K/AKoppers Holdings Inc.KOPMay 7

    Current report (amended)

29. SCHEDULE 13GKoppers Holdings Inc.KOPApr 30

    Ownership stake disclosure by VANGUARD CAPITAL MANAGEMENT LLC

    VANGUARD CAPITAL MANAGEMENT LLC, filed by

30. ARSKoppers Holdings Inc.KOPMar 27

    Annual report to shareholders

31. DEF 14AKoppers Holdings Inc.KOPMar 27

    Proxy statement

32. SCHEDULE 13G/AKoppers Holdings Inc.KOPMar 27

    Ownership stake disclosure by VANGUARD GROUP INC (amended)

    VANGUARD GROUP INC, filed by

33. 4Koppers Holdings Inc.KOPMar 25

    2 insider filings

    Sonja Michelle Wilkerson, insider filing for KOP

    Show all 2

    • 4Insider filing for KOPMar 25
    • 4Insider filing for KOPMar 25

    Sonja Michelle Wilkerson, reporting

Older filings on EDGAR