ECP ControlCo Form 4 Change in insider ownership

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

X

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

1. Name and Address of Reporting Person^*

ECP ControlCo, LLC

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

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)

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

3. Date of Earliest Transaction (Month/Day/Year)
09/05/2024

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

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

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

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	09/05/2024		S		2,354,109	D	$3.42(1)	23,384,879	I	See footnotes(2)(3)(4)(5)

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

1. Name and Address of Reporting Person^*

ECP ControlCo, LLC

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III, LLC

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Energy Capital Partners GP III, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III-A, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III-B, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III-C, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS III-D, LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ENERGY CAPITAL PARTNERS GP III CO-INVESTMENT (NESCO), LLC

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Energy Capital Partners III (NESCO Co-Invest), LP

(Last) (First) (Middle)

40 BEECHWOOD ROAD

(Street)

SUMMIT, NJ 07901

(City) (State) (Zip)

Explanation of Responses:

1. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.42 to $3.72. The reporting persons undertake to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

2. Following the transactions reported herein, ECP Cardinal Holdings, LP and NESCO Holdings, LP are the record holders of 4,088,426 and 19,296,453 shares of Common Stock, respectively.

3. ECP ControlCo, LLC is controlled by its board of managers, which consists of Douglas Kimmelman, Peter Labbat, Tyler Reeder, Rahman D'Argenio, Raoul Hughes and Xavier Robert (together, the "ECP Managers"), all of whom collectively share the power to vote and dispose of the securities beneficially owned by ECP ControlCo, LLC. As a result of the relationships described below, each of the ECP Managers may be deemed to share beneficial ownership of the securities described herein. Each individual disclaims beneficial ownership of such securities.

4. ECP ControlCo, LLC is the managing member of Energy Capital Partners III, LLC, which is the general partner of (i) Energy Capital Partners GP III, LP, which is the general partner of each of Energy Capital Partners III, LP, Energy Capital Partners III-A, LP, Energy Capital Partners III-B, LP, Energy Capital Partners III-C, LP, and Energy Capital Partners III-D, LP, which are the sole members of ECP Starlight Public GP, LLC, which is the general partner of ECP Starlight Guarantor (Public), LP, and (ii) Energy Capital Partners GP III Co-Investment (NESCO), LLC, which is the general partner of Energy Capital Partners III (NESCO Co-Invest), LP.

5. ECP Starlight Guarantor (Public), LP and Energy Capital Partners III (NESCO Co-Invest), LP are the sole members of NESCO Holdings GP, LLC, which is the general partner of each of ECP Cardinal Holdings, LP and NESCO Holdings, LP. Each of the entities described in footnotes 4 and 5 may be deemed to share beneficial ownership of the securities held of record by ECP Cardinal Holdings, LP and NESCO Holdings, LP.

Remarks:

Due to filing limitations of the electronic filing system, each of ECP Starlight Public GP, LLC, ECP Starlight Guarantor (Public), LP, NESCO Holdings GP, LLC, NESCO Holdings, LP and ECP Cardinal Holdings, LP are filing a separate Form 4.

	ECP ControlCo, LLC, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III, LLC, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners GP III, LP, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III, LP, By: Energy Capital Partners GP III, LP, its general partner, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III-A, LP, By: Energy Capital Partners GP III, LP, its general partner, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III-B, LP, By: Energy Capital Partners GP III, LP, its general partner, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III-C, LP, By: Energy Capital Partners GP III, LP, its general partner, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III-D, LP, By: Energy Capital Partners GP III, LP, its general partner, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners GP III Co-Investment (NESCO), LLC, By: Energy Capital Partners III, LLC, its general partner, By: ECP ControlCo, LLC, its managing member, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	Energy Capital Partners III (NESCO Co-Invest), LP, By: Energy Capital Partners GP III Co-Investment (NESCO), LLC, By: Energy Capital Partners III, LLC, By: ECP ControlCo, LLC, By: /s/ Rahman D'Argenio, Managing Member	09/09/2024
	** 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.