Cabot Corp (CBT) SVP reports 228.6 phantom stock units under 401(k) plan

Rhea-AI Filing Summary

Cabot Corporation senior vice president reports acquisition of phantom stock units. A Cabot Corp (CBT) officer filed details of a compensation-related transaction dated 12/31/2025. The filing shows the officer acquired 228.5882 phantom stock units linked to Cabot common stock at a price of $66.28 per unit. Each phantom stock unit is described as convertible on a 1-for-1 basis into Cabot common shares. After this transaction, the officer held 520.4248 derivative securities, reported as directly owned. The phantom stock units were acquired under the company’s supplemental 401(k) plan and are to be settled when the reporting person retires or otherwise terminates service.

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^*

Masterson William F III

(Last) (First) (Middle)

C/O CABOT CORPORATION

TWO SEAPORT LANE, SUITE 1400

(Street)

BOSTON MA 02210

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CABOT CORP [ CBT ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2025

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

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

X	Form filed by One Reporting Person
	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

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
Phantom Stock Units	(1)	12/31/2025		A		228.5882		(2)	(2)	Common Stock	228.5882	$66.28	520.4248	D

Explanation of Responses:

1. 1 for 1

2. The reported phantom stock units were acquired under the Corporation's supplemental 401(k) plan and are to be settled upon the reporting person's retirement or other termination of service.

	By: Mazda Cintron, pursuant to a power of attorney from William F. Masterson, III	01/05/2026
	** 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.

FAQ

What insider transaction did Cabot Corp (CBT) report in this Form 4?

The filing reports that a Cabot Corp senior vice president acquired 228.5882 phantom stock units tied to Cabot common stock on 12/31/2025.

What are the terms of the phantom stock units reported by Cabot Corp (CBT)?

The phantom stock units are described as 1 for 1, meaning each unit corresponds to one share of Cabot common stock, with an indicated price of $66.28 per unit.

How many derivative securities does the Cabot Corp (CBT) officer own after this transaction?

Following the reported acquisition, the officer beneficially owns 520.4248 derivative securities, reported with direct ownership.

Under which plan were the Cabot Corp (CBT) phantom stock units acquired?

The filing states that the phantom stock units were acquired under the Corporation's supplemental 401(k) plan.

When will the Cabot Corp (CBT) phantom stock units be settled?

The phantom stock units are to be settled upon the reporting person's retirement or other termination of service.

What is the reporting person’s role at Cabot Corp (CBT)?

The reporting person is identified as an officer of Cabot Corp with the title Senior Vice President.

Is this Cabot Corp (CBT) Form 4 filed for one person or multiple insiders?

The document indicates it is a Form filed by one reporting person, not a joint filing.