PLATINUM EQUITY, LLC - 12 Jan 2026 Form 3 Insider Report for CompoSecure, Inc. (CMPO)

Reporting relationship: 10%+ Owner
Issuer ticker: CMPO
Reported as of: 12 Jan 2026
Net transaction value: $0
SEC form: 3
Accepted by SEC: 20 Jan 2026, 16:30:34 UTC
Prior SEC filing: 23 Jul 2025
Next SEC filing: 11 Mar 2026
Source filing: View source filing
Reporting owner signature: Platinum Equity, LLC, By: /s/ Mary Ann Sigler, Executive Vice President, Chief Financial Officer and Treasurer

Key filing fact

PLATINUM EQUITY, LLC filed Form 3 for CompoSecure, Inc. (CMPO) on 20 Jan 2026.

Key facts

This page summarizes PLATINUM EQUITY, LLC's Form 3 filing for CompoSecure, Inc. (CMPO).
0 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 20 Jan 2026, 16:30.

Change

Previous filing in this sequence was filed on 23 Jul 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Official SEC source

Ownership activity is grounded in SEC Form 3 disclosures.

View source filing

Reporting Owners (9)

CIK 0001228754 Primary reporting owner

PLATINUM EQUITY, LLC

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity, LLC, By: /s/ Mary Ann Sigler, Executive Vice President, Chief Financial Officer and Treasurer
Signature date: 20 Jan 2026

CIK 0001634372

Platinum Equity Investment Holdings, LLC

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity Investment Holdings, LLC, By: /s/ Mary Ann Sigler, Vice President, Secretary and Treasurer
Signature date: 20 Jan 2026

CIK 0001756330

Platinum Equity Investment Holdings IC (Cayman), LLC

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity Investment Holdings IC (Cayman), LLC, By: /s/ Mary Ann Sigler, President
Signature date: 20 Jan 2026

CIK 0001756331

Platinum Equity InvestCo, L.P.

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity InvestCo, L.P., By: Platinum Equity Investment Holdings IC (Cayman), LLC, its general partner, By: /s/ Mary Ann Sigler, President
Signature date: 20 Jan 2026

CIK 0001756333

Platinum Equity Investment Holdings IV, LLC

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity Investment Holdings IV, LLC, By: /s/ Ty Renbarger, Vice President
Signature date: 20 Jan 2026

CIK 0001785531

Platinum Equity Investment Holdings IV (Cayman), LLC

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity Investment Holdings IV (Cayman), LLC, By: /s/ Ty Renbarger, Vice President
Signature date: 20 Jan 2026

CIK 0001785528

Platinum Equity Partners International IV (Cayman), L.P.

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Platinum Equity Partners International IV (Cayman), L.P., By: Platinum Equity Investment Holdings IV (Cayman), LLC, its general partner, By: /s/ Ty Renbarger, Vice President
Signature date: 20 Jan 2026

CIK 0002104295

PE Titan CS Holdings, L.P.

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: PE Titan CS Holdings, L.P., By: Platinum Equity Partners International IV (Cayman), L.P., its GP, By Platinum Equity Investment Holdings IV (Cayman), LLC, its GP, By: /s/ Ty Renbarger, Vice President
Signature date: 20 Jan 2026

CIK 0001471783

Gores Tom

Relationship: 10%+ Owner
Address: C/O PLATINUM EQUITY ADVISORS, LLC, 360 NORTH CRESCENT DRIVE, SOUTH BUILDING, BEVERLY HILLS
Signature: Tom Gores, By: /s/ Mary Ann Sigler, Attorney-in-Fact
Signature date: 20 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CMPO holding

Class A Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 52,829,757
Date: 12 Jan 2026
Ownership: See footnote
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

PE Titan CS Holdings, L.P. (the "Platinum Stockholder") is the record holder of the securities reported herein. Tom Gores is the manager of Platinum Equity, LLC, which is the sole member of Platinum Equity Investment Holdings, LLC, which is the sole member of Platinum Equity Investment Holdings IC (Cayman), LLC, which is the general partner of Platinum Equity InvestCo, L.P., which is the sole member of Platinum Equity Investment Holdings IV, LLC, which is the sole member of Platinum Equity Investment Holdings IV (Cayman), LLC, which is the general partner of Platinum Equity Partners International IV (Cayman), L.P., which is the general partner of the Platinum Stockholder. By virtue of these relationships, each of these entities and Mr. Gores may be deemed to share beneficial ownership of the securities held of record by the Platinum Stockholder.

SEC remarks

Exhibit 24 - Power of Attorney.