PLATINUM EQUITY, LLC - 12 Jan 2026 SCHEDULE 13D Report for CompoSecure, Inc. Class A Common Stock, par value $0.0001 per share (CMPO)

Filing manager: PLATINUM EQUITY, LLC
Reporting owner: Platinum Equity, LLC
Security: CompoSecure, Inc. Class A Common Stock, par value $0.0001 per share
Beneficially owned shares: 52,829,757 shares
Large-stake signal: Form
SCHEDULE 13D
Active or control-oriented beneficial ownership filing.
Ownership
18%
Beneficial ownership of this reported class.
Shares
52,829,757 shares
Shares beneficially owned as disclosed.
Event date
12 Jan 2026
Date tied to the ownership event or amendment.
Accepted by SEC
20 Jan 2026
EDGAR 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: 18%
Symbol: CMPO
Shares outstanding: 288,687,197 shares
SEC form: SCHEDULE 13D
Accepted by SEC: 20 Jan 2026, 16:30:10 UTC
Event date: 12 Jan 2026
Source filing: View source filing

Key filing fact

PLATINUM EQUITY, LLC disclosed 18% ownership in CompoSecure, Inc. Class A Common Stock, par value $0.0001 per share (CMPO) on 12 Jan 2026.

Key facts

PLATINUM EQUITY, LLC filed SCHEDULE 13D for CompoSecure, Inc. Class A Common Stock, par value $0.0001 per share (CMPO).
Disclosed ownership: 18%.
Date of event: 12 Jan 2026.

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.

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

Reporting persons

Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.

Name	Ownership	Shares owned	Shared voting power	Signature	Title	CIK
Platinum Equity, LLC	18%	52,829,757	52,829,757	/s/ Mary Ann Sigler	Mary Ann Sigler, Executive Vice President, Chief Financial Officer and Treasurer	0001228754
Platinum Equity Investment Holdings, LLC	18%	52,829,757	52,829,757	/s/ Mary Ann Sigler	Mary Ann Sigler, Vice President, Secretary and Treasurer	0001634372
Platinum Equity Investment Holdings IC (Cayman), LLC	18%	52,829,757	52,829,757	/s/ Mary Ann Sigler	Mary Ann Sigler, President	0001756330
Platinum Equity InvestCo, L.P.	18%	52,829,757	52,829,757	By: Platinum Equity Investment Holdings IC (Cayman), LLC, its general partner, /s/ Mary Ann Sigler	Mary Ann Sigler, President	0001756331
Platinum Equity Investment Holdings IV, LLC	18%	52,829,757	52,829,757	/s/ Ty Renbarger	Ty Renbarger, Vice President	0001756333
Platinum Equity Investment Holdings IV (Cayman), LLC	18%	52,829,757	52,829,757	/s/ Ty Renbarger	Ty Renbarger, Vice President	0001785531
Platinum Equity Partners International IV (Cayman), L.P.	18%	52,829,757	52,829,757	By: Platinum Equity Investment Holdings IV (Cayman), LLC, its general partner, /s/ Ty Renbarger	Ty Renbarger, Vice President	0001785528
PE Titan CS Holdings, L.P.	18%	52,829,757	52,829,757	By: Platinum Equity Partners International IV (Cayman), L.P., its GP, Platinum Equity Investment Holdings IV (Cayman), LLC, its GP, /s/ Ty Renbarger	Ty Renbarger, Vice President	0002104295
Tom Gores	18%	52,829,757	52,829,757	/s/ Mary Ann Sigler	Mary Ann Sigler, Attorney-in-Fact	0001471783

CIK / CUSIP context first

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