Form 4 Filing for Custom Truck One Source, Inc.

This filing details significant stock transactions by Ryan McMonagle, the Chief Executive Officer and a director of Custom Truck One Source, Inc. On April 1, 2026, McMonagle acquired 121,875 shares of common stock with a transaction price of $0.00. In a separate transaction on the same date, 54,906 shares were disposed of at a price of $6.62 per share, resulting in a post-transaction ownership of 695,984 shares. Additionally, the filing reports transactions involving Restricted Stock Units (RSUs). McMonagle disposed of 81,250 RSUs, vested in installments starting April 1, 2024, and 40,625 RSUs, vested in installments starting April 1, 2026. He also acquired 175,000 RSUs, which vest in installments starting April 1, 2027. Each RSU represents a contingent right to one share of the company's common stock. Footnote 2 specifies that shares were withheld to cover tax obligations from vested RSUs.