Cabot insider plans $11.5M stock sale

CABOT CORP (CBT) is named as the issuer in a Form 144 filing relating to planned sales of its common stock by Sean D. Keohane.

Rhea-AI Filing Summary

CABOT CORP (CBT) is named as the issuer in a Form 144 filing relating to planned sales of its common stock by Sean D. Keohane. The notice covers up to 134,895 shares of common stock, to be sold following a stock option exercise on August 28, 2026, with sales reported on the NYSE.

Key Figures

Shares covered by Form 144: 134,895 shares of common stock Aggregate market value of shares covered: $11,466,075.00 Recent sale on 08/07/2026: 91,923 shares for $7,942,634.39 +2 more

5 metrics

Shares covered by Form 144 134,895 shares of common stock Securities information section for planned sales as of 08/28/2026

Aggregate market value of shares covered $11,466,075.00 Market value associated with 134,895 CABOT CORP common shares

Recent sale on 08/07/2026 91,923 shares for $7,942,634.39 Securities sold during the past 3 months by Sean D. Keohane

Recent sale on 08/24/2026 2,779 shares for $237,604.50 Securities sold during the past 3 months by Sean D. Keohane

Planned sale date reference 08/28/2026 Date tied to stock option exercise and securities to be sold

Key Terms

Rule 144, stock option exercise, attorney-in-fact

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

stock option exercise financial

"Common | 08/28/2026 | Stock Option Exercise | Issuer"

A stock option exercise is the act of using a previously granted right to buy shares of a company's stock at a specific, predetermined price by paying that price and receiving the shares. It matters to investors because exercising changes who owns the shares (which can dilute existing ownership), can trigger taxable events and shift potential gains or losses, and affects voting power and the company’s outstanding share count—like turning a voucher into an actual product that becomes part of circulating supply.

attorney-in-fact regulatory

"as attorney-in-fact for Sean D. Keohane"

An attorney-in-fact is the person or entity given legal authority through a power of attorney to act on behalf of another for specific tasks, such as signing documents, voting shares, or handling transactions. For investors, this matters because it lets a trusted representative make timely decisions or complete paperwork when the owner cannot, much like handing keys to someone to run errands on your behalf—so checks on scope and limits of that authority are important.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does this Form 144 filing mean for CABOT CORP (CBT)?

The filing reports that Sean D. Keohane has given notice under Rule 144 of an intent to sell up to 134,895 CABOT CORP common shares following a stock option exercise on August 28, 2026. It is a regulatory disclosure of potential insider sales.

How many CABOT CORP (CBT) shares are covered by the new Form 144 notice?

The notice covers up to 134,895 CABOT CORP common shares. These shares are associated with a stock option exercise dated August 28, 2026, and the planned sales are listed as occurring on the NYSE through Fidelity Brokerage Services LLC.

What is the aggregate market value of CABOT CORP (CBT) shares in this Form 144?

The Form 144 lists an aggregate market value of approximately $11,466,075.00 for the 134,895 CABOT CORP common shares covered under the notice, based on the representative market price information provided in the filing.

What CABOT CORP (CBT) stock sales has Sean D. Keohane made in the last 3 months?

The filing reports that Sean D. Keohane sold 91,923 CABOT CORP common shares on August 7, 2026 for about $7,942,634.39 and 2,779 shares on August 24, 2026 for about $237,604.50 during the prior three months.

Who is executing the CABOT CORP (CBT) Form 144 sale for Sean D. Keohane?

The securities are to be sold through Fidelity Brokerage Services LLC. The Form 144 is signed by Louis Kurnick as a duly authorized representative of Fidelity, acting as attorney-in-fact for Sean D. Keohane.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/28/2026 - 10:21 AM EDT Accepted by SEC EDGAR 08/28/2026 - 10:21 AM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001435737
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	CABOT CORP
SEC File Number	001-05667
Address of Issuer	TWO SEAPORT LANE SUITE 1400 BOSTON MASSACHUSETTS 02210
Phone	6173450100
Name of Person for Whose Account the Securities are To Be Sold	Keohane Sean D
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Fidelity Brokerage Services LLC 900 Salem Street Smithfield RI 02917	134895	11466075.00	51631007	08/28/2026	NYSE

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/28/2026	Stock Option Exercise	Issuer			134895	08/28/2026	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Sean D. Keohane Two Seaport Lane Suite 1400 Boston MA 02210-2019	Common	08/07/2026	91923	7942634.39
Sean D. Keohane Two Seaport Lane Suite 1400 Boston MA 02210-2019	Common	08/24/2026	2779	237604.50

144: Remarks and Signature

Remarks
Date of Notice	08/28/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Louis Kurnick, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Sean D. Keohane
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)