CTOS (CTOS) director adds equity via RSU exercise and 175K-unit grant

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Custom Truck One Source, Inc. director Frederick M. Ross, Jr. reported equity compensation activity involving restricted stock units and common stock on April 1, 2026. He exercised restricted stock units covering 131,250 shares of common stock, and 39,441 shares were withheld at $6.62 per share to cover tax obligations related to vesting.

Ross also received a new grant of 175,000 restricted stock units, which vest in four equal annual installments beginning on April 1, 2027, subject to continued service and potential partial acceleration upon certain corporate milestones. Following these transactions, he directly owns 540,188 shares of common stock and indirectly holds 2,000,000 shares through Frederick M. Ross, Jr. Holding Company, LLC.

Insider Trade Summary

131,250 shares exercised/converted

Mixed 6 txns

Insider Ross Fredrick M. Jr.

Role Director

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Unit	87,500	$0.00	--
Exercise	Restricted Stock Unit	43,750	$0.00	--
Grant/Award	Restricted Stock Unit	175,000	$0.00	--
Exercise	Common Stock	131,250	$0.00	--
Tax Withholding	Common Stock	39,441	$6.62	$261K
holding	Common Stock	--	--	--

Holdings After Transaction: Restricted Stock Unit — 87,500 shares (Direct); Common Stock — 579,629 shares (Direct); Common Stock — 2,000,000 shares (Indirect, By Frederick M. Ross, Jr. Holding Company, LLC)

Footnotes (1)

Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. Shares withheld to satisfy tax obligations arising out of vesting of the Reporting Person's restricted stock units. The restricted stock units vest in four equal annual installments beginning on April 1, 2024. The restricted stock units vest in four equal annual installments beginning on April 1, 2026. The restricted stock units vest in four equal annual installments beginning on April 1, 2027, subject to continued service on the applicable vesting date and potential partial acceleration upon the achievement of certain corporate milestones.

Key Figures

RSUs exercised into common stock: 131,250 shares Shares withheld for taxes: 39,441 shares at $6.62 New RSU grant: 175,000 units +2 more

5 metrics

RSUs exercised into common stock 131,250 shares Restricted stock units converted to CTOS common stock on April 1, 2026

Shares withheld for taxes 39,441 shares at $6.62 Tax withholding on RSU vesting on April 1, 2026

New RSU grant 175,000 units Restricted stock units granted with vesting from April 1, 2027

Direct common stock holdings 540,188 shares Direct CTOS shares held after transactions on April 1, 2026

Indirect common stock holdings 2,000,000 shares Indirect CTOS shares held via Frederick M. Ross, Jr. Holding Company, LLC

Key Terms

Restricted Stock Unit, tax obligations, vesting, indirect ownership, +1 more

5 terms

Restricted Stock Unit financial

"Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock."

A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.

tax obligations financial

"Shares withheld to satisfy tax obligations arising out of vesting of the Reporting Person's restricted stock units."

vesting financial

"The restricted stock units vest in four equal annual installments beginning on April 1, 2027."

Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.

indirect ownership financial

"Indirect ownership of 2,000,000 common shares by Frederick M. Ross, Jr. Holding Company, LLC."

corporate milestones financial

"Potential partial acceleration upon the achievement of certain corporate milestones."

Form 4 Insider Transactions: What Each Field Means →

04/03/2026 - 06:07 PM

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)
04/01/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	04/01/2026		M		131,250⁽¹⁾	A	$0	579,629	D
Common Stock	04/01/2026		F		39,441⁽²⁾	D	$6.62	540,188	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Unit	⁽¹⁾	04/01/2026		M			87,500	⁽³⁾	⁽³⁾	Common Stock	87,500	$0	87,500	D
Restricted Stock Unit	⁽¹⁾	04/01/2026		M			43,750	⁽⁴⁾	⁽⁴⁾	Common Stock	43,750	$0	131,250	D
Restricted Stock Unit	⁽¹⁾	04/01/2026		A		175,000		⁽⁵⁾	⁽⁵⁾	Common Stock	175,000	$0	175,000	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock.

2. Shares withheld to satisfy tax obligations arising out of vesting of the Reporting Person's restricted stock units.

3. The restricted stock units vest in four equal annual installments beginning on April 1, 2024.

4. The restricted stock units vest in four equal annual installments beginning on April 1, 2026.

5. The restricted stock units vest in four equal annual installments beginning on April 1, 2027, subject to continued service on the applicable vesting date and potential partial acceleration upon the achievement of certain corporate milestones.

	By: /s/ Paul M. Jolas, Attorney-in-fact	04/03/2026
	** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transactions did CTOS director Frederick M. Ross, Jr. report?

Frederick M. Ross, Jr. reported exercising restricted stock units into 131,250 CTOS common shares and receiving a grant of 175,000 new restricted stock units. In addition, 39,441 shares of common stock were withheld to satisfy tax obligations arising from the vesting of his restricted stock units.

How many Custom Truck One Source (CTOS) shares does Frederick M. Ross, Jr. now hold directly and indirectly?

After the reported transactions, Ross directly owns 540,188 CTOS common shares. He also indirectly holds 2,000,000 additional shares through Frederick M. Ross, Jr. Holding Company, LLC, reflecting both his personal and entity-associated equity exposure to Custom Truck One Source, Inc.

What are the terms of the 175,000 CTOS restricted stock units granted to Frederick M. Ross, Jr.?

Ross received a grant of 175,000 CTOS restricted stock units that vest in four equal annual installments beginning on April 1, 2027. Vesting is subject to his continued service and may partially accelerate upon achievement of specified corporate milestones, according to the filing footnotes.

Why were 39,441 CTOS shares disposed of in Frederick M. Ross, Jr.’s Form 4 filing?

The 39,441 CTOS shares were withheld by the issuer to satisfy tax obligations related to the vesting of Ross’s restricted stock units. This tax-withholding disposition is not an open-market sale and reflects standard treatment of equity compensation tax liabilities.

How do the exercised restricted stock units affect Frederick M. Ross, Jr.’s CTOS common stock position?

Ross exercised restricted stock units representing 131,250 CTOS common shares, increasing his direct share ownership. After withholding 39,441 shares for taxes, his direct common stock holdings rose to 540,188 shares, as disclosed in the post-transaction ownership figures in the Form 4.

What do the CTOS Form 4 footnotes say about the nature of the restricted stock units?

The footnotes explain each CTOS restricted stock unit represents a contingent right to receive one common share. They also describe vesting schedules beginning April 1, 2024, April 1, 2026, and April 1, 2027, with some awards subject to continued service and certain corporate milestone conditions.