William F. Masterson III - 03 Dec 2025 Form 4 Insider Report for CABOT CORP (CBT)

Role: Senior Vice President
Signature: By: Jennifer Lombardi, pursuant to a power of attorney from William F. Masterson, III
Issuer symbol: CBT
Transactions as of: 03 Dec 2025
Net transactions value: $0
Form type: 4
Filing time: 05 Dec 2025, 17:30:04 UTC
Previous filing: 02 Dec 2025
Next filing: 16 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Masterson William F III	Senior Vice President	C/O CABOT CORPORATION, TWO SEAPORT LANE, SUITE 1400, BOSTON	By: Jennifer Lombardi, pursuant to a power of attorney from William F. Masterson, III	05 Dec 2025	0002098902

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CBT	Common Stock	Award	$0	+3,486	+94%	$0.000000	7,210	03 Dec 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CBT	Employee Stock Option (Right to Buy)	Award	$0	+12,767		$0.000000	12,767	03 Dec 2025	Common Stock	12,767	$64.54	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The option vests over a three year period as follows: 30% on December 3, 2026, 30% on December 3, 2027 and 40% on December 3, 2028.