Form
SCHEDULE 13D
Active or control-oriented beneficial ownership filing.
Simcoe Capital Management, LLC - 12 May 2026 SCHEDULE 13D Report for Koppers Holdings Inc. Common Stock (KOP)
- Filing manager
- Simcoe Capital Management, LLC
- Reporting owner
- Simcoe Capital Management, LLC
- Security
- Koppers Holdings Inc. Common Stock
- Beneficially owned shares
- 1,349,005 shares
- Large-stake signal
-
Ownership
7%Beneficial ownership of this reported class.
Shares
1,349,005 sharesShares beneficially owned as disclosed.
Event date
12 May 2026Date tied to the ownership event or amendment.
Accepted by SEC
19 May 2026EDGAR acceptance date.
How to read this large-stake filing
- Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
- Compare this filing with the holder history and issuer page before treating the percentage as a current position.
- Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
- Class ownership
- 7%
- Symbol
- KOP
- Shares outstanding
- 19,271,500 shares
- SEC form
- SCHEDULE 13D
- Accepted by SEC
- 19 May 2026, 17:33:04 UTC
- Event date
- 12 May 2026
- Source filing
- View source filing
Ownership signal
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Subject security
Names, identifiers, and filing context for this profile.
2 source fields
Source evidence
Original filing metadata and source links for verification.
4 source fields
Key filing fact
Simcoe Capital Management, LLC disclosed 7% ownership in Koppers Holdings Inc. Common Stock (KOP) on 12 May 2026.
Key facts
- Simcoe Capital Management, LLC filed SCHEDULE 13D for Koppers Holdings Inc. Common Stock (KOP).
- Disclosed ownership: 7%.
- Date of event: 12 May 2026.
Change
- No earlier schedule filing is available for direct comparison.
- Current filing was accepted on 19 May 2026, 17:33.
Research use
- This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
- Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.
Evidence
Backed by Schedule 13D/13G
View source filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting persons
Disclosed reporting parties (6)
Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.
| Name | Ownership | Shares owned | Sole voting power | Shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Simcoe Capital Management, LLC | 7% | 1,349,005 | 1,349,005 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz, Managing Member | 0001633362 |
| SIMCOE PARTNERS L P | 6.4% | 1,226,375 | 1,226,375 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz, Managing Member of Simcoe Management Company, LLC (its General Partner) | 0001220336 |
| Simcoe Select, LP | 0.5% | 86,845 | 86,845 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz, Managing Member of Simcoe Management Company, LLC (its General Partner) | 0001758330 |
| SIMCOE MANAGEMENT COMPANY, LLC | 6.8% | 1,313,220 | 1,313,220 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz, Managing Member | |
| SDR Partners, LLC | 0.2% | 35,785 | 35,785 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz, Managing Member of Simcoe Management Company, LLC (its Investment Manager) | 0001538519 |
| Jacobowitz Jeffrey | 7% | 1,349,005 | 1,349,005 | 0 | /s/ Jeffrey Jacobowitz | Jeffrey Jacobowitz | 0001450714 |
CIK / CUSIP context first