CTOS (CTOS) director Ross granted 43,392 performance stock award shares

Rhea-AI Filing Summary

Ross Fredrick M. Jr. reported acquisition or exercise transactions in this Form 4 filing.

Custom Truck One Source director Fredrick M. Ross, Jr. reported receiving 43,392 shares of Common Stock as a stock-based award. These shares were earned under performance stock unit awards for a performance period that ended on December 31, 2025 and were certified by the compensation committee on February 23, 2026.

The granted shares still have a time-based vesting requirement and will vest on December 31, 2026. After this grant, Ross directly owns 448,379 shares and also has an indirect holding of 2,000,000 shares through Frederick M. Ross, Jr. Holding Company, LLC.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Ross Fredrick M. Jr.

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	43,392	$0.00	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 448,379 shares (Direct); Common Stock — 2,000,000 shares (Indirect, By Frederick M. Ross, Jr. Holding Company, LLC)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Ross Fredrick M. Jr.

(Last) (First) (Middle)

7701 INDEPENDENCE AVE

(Street)

KANSAS CITY MISSOURI 64125

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Custom Truck One Source, Inc. [ CTOS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
02/23/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/23/2026		A		43,392(1)	A	$0	448,379	D
Common Stock								2,000,000	I	By Frederick M. Ross, Jr. Holding Company, LLC

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents an award of performance stock units ("PSUs") earned as a result of the achievement of performance criteria pursuant to PSU awards with a performance period that ended on December 31, 2025, as certified by the compensation committee of the Issuer's board of directors on February 23, 2026. Such shares remain subject to a time-based vesting condition, which will be satisfied on December 31, 2026.

	/s/ Paul M. Jolas, Attorney-in-fact	03/26/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Custom Truck One Source (CTOS) report for Fredrick M. Ross, Jr.?

Custom Truck One Source reported that director Fredrick M. Ross, Jr. received 43,392 shares of Common Stock as a stock-based award. The shares were earned from performance stock units tied to a performance period ending December 31, 2025 and certified on February 23, 2026.

What type of shares did CTOS director Fredrick M. Ross, Jr. receive in this Form 4 filing?

The Form 4 shows an acquisition of 43,392 shares of CTOS Common Stock through a grant or award. These shares represent performance stock units that were earned based on achieved performance criteria and converted into shares, with no cash purchase price paid per share.

Are the newly awarded CTOS shares to Fredrick M. Ross, Jr. fully vested?

No, the newly awarded shares are not fully vested. Although the performance criteria were achieved for the period ending December 31, 2025, the shares remain subject to time-based vesting and will vest on December 31, 2026, assuming the vesting condition is satisfied.

How many CTOS shares does Fredrick M. Ross, Jr. hold after this reported award?

After the award, Fredrick M. Ross, Jr. directly holds 448,379 shares of Custom Truck One Source Common Stock. The filing also reports an indirect holding of 2,000,000 shares through Frederick M. Ross, Jr. Holding Company, LLC, reflecting additional ownership via that entity.

What is the role of performance stock units (PSUs) in the CTOS award to Ross?

The 43,392 shares represent performance stock units earned after meeting specified performance goals for a period ending December 31, 2025. Once the compensation committee certified results on February 23, 2026, the PSUs converted into shares that will vest over time, completing on December 31, 2026.

Does the CTOS Form 4 indicate any stock sales by Fredrick M. Ross, Jr.?

The Form 4 does not report any stock sales by Fredrick M. Ross, Jr. It shows an acquisition of shares through a grant or award and includes a separate holding entry for his indirect ownership via Frederick M. Ross, Jr. Holding Company, LLC without indicating a sale transaction.