SCHEDULE: Mark Ein Reduces Stake in Custom Truck One Source

An amendment to Schedule 13D reveals a distribution-in-kind by Capitol Acquisition Management IV LLC, resulting in the reporting group ceasing to be a 5% beneficial owner of Custom Truck One Source, Inc. common stock.

Summary

• Capitol Acquisition Management IV LLC distributed 3,670,279 shares of Custom Truck One Source, Inc. (CTOS) Common Stock to its members without consideration on October 17, 2025.
• As a result of this distribution, Mark Ein acquired 3,553,612 shares of Common Stock.
• Following the distribution, the Reporting Persons (Capitol Acquisition Management IV LLC, Capitol Acquisition Founder IV LLC, Mark Ein, and Dyson Dryden) have collectively ceased to be the beneficial owners of more than five percent of the outstanding Common Stock.
• Mark Ein now beneficially owns 5,159,319 shares of Common Stock, which includes 5,139,319 record shares and options to purchase 20,000 shares, representing 2.3% of the class.
• Capitol Acquisition Management IV LLC, Capitol Acquisition Founder IV LLC, and Dyson Dryden each beneficially own 0 shares of Common Stock.

Sentiment

Score: 4

Explanation: The sentiment is slightly negative as the original reporting group, which was a significant beneficial owner, has reduced its collective stake below the 5% threshold, signaling a potential decrease in institutional commitment, despite Mark Ein's increased individual direct holdings.

Positives

• Mark Ein, a key individual from the original reporting group, significantly increased his direct personal holdings by 3,553,612 shares through the distribution.

Negatives

• The original reporting group (Capitol Acquisition Management IV LLC and Capitol Acquisition Founder IV LLC) has ceased to be a beneficial owner of more than five percent of Custom Truck One Source, Inc. common stock, indicating a reduction in their collective formal stake.
• Capitol Acquisition Management IV LLC and Capitol Acquisition Founder IV LLC now hold 0 shares beneficially.

Future Outlook

The filing does not provide any forward-looking statements or guidance regarding the company's future performance or operations.

Industry Context

This filing pertains to a change in beneficial ownership by an insider group and does not provide information related to broader industry trends or competitive landscape.

Related Party Transactions

• Capitol Acquisition Management IV LLC distributed 3,670,279 shares of Common Stock to its members, including Mark Ein, on a pro rata basis without consideration. This constitutes a related party transaction as it involves entities and individuals previously associated as reporting persons.

Stakeholder Impact

• Shareholders may interpret the reduction of the original reporting group's collective beneficial ownership below 5% as a signal of reduced institutional confidence or strategic shift by a significant insider group.

Key Dates

Recommendation

The original reporting group, including Capitol Acquisition Management IV LLC and Capitol Acquisition Founder IV LLC, has ceased to be a beneficial owner of more than 5% of the outstanding common stock. This distribution-in-kind, while increasing Mark Ein's direct holdings, signifies a reduction in the collective formal stake of the original insider group, which can be viewed as a negative signal by investors. However, Mark Ein still retains a substantial individual stake, warranting a 'hold' rather than a 'sell' recommendation without further operational or financial insights.

Keywords

Custom Truck One Source, CTOS, Schedule 13D, Beneficial Ownership, Insider Ownership, Stock Distribution, Mark Ein, Capitol Acquisition Management IV LLC, Capitol Acquisition Founder IV LLC