Mark D. Ein - 17 Oct 2025 Form 4 Insider Report for Custom Truck One Source, Inc. (CTOS)

Reporting relationship: Director
Issuer ticker: CTOS
Reported as of: 17 Oct 2025
Net transaction value: $0
SEC form: 4
Accepted by SEC: 21 Oct 2025, 16:30:02 UTC
Prior SEC filing: 12 Aug 2025
Next SEC filing: 20 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Mark Ein

Key filing fact

Mark D. Ein filed Form 4 for Custom Truck One Source, Inc. (CTOS) on 21 Oct 2025.

Key facts

This page summarizes Mark D. Ein's Form 4 filing for Custom Truck One Source, Inc. (CTOS).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 21 Oct 2025, 16:30.

Change

Previous filing in this sequence was filed on 12 Aug 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

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001246840 Primary reporting owner

EIN MARK

Relationship: Director
Address: 7701 INDEPENDENCE AVE., KANSAS CITY
Signature: /s/ Mark Ein
Signature date: 21 Oct 2025

Reported non-derivative transactions

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

CTOS transaction

Common Stock

Other

Transaction value: $0
Shares: -3,670,279
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 17 Oct 2025
Ownership: By Capitol Acquisition Management IV, LLC
Footnotes: F1

CTOS holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 5,139,319
Date: 17 Oct 2025
Ownership: Direct
Footnotes: F2

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Represents a pro-rata distribution in-kind by Capitol Acquisition Management IV, LLC to its members for no consideration (the "Distribution").

Footnote F2

Includes shares received in the Distribution.

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