X0306 4 2018-05-31 0 0000016040 CABOT CORP CBT 0001243739 BERUBE BRIAN A C/O CABOT CORPORATION TWO SEAPORT LANE, SUITE 1300 BOSTON MA 02210 0 1 0 0 SVP, General Counsel Common Stock 2018-05-31 4 S 0 7311 60.30 D 45759 D Common Stock 8615.2263 I Through the Trustee of the Corporation's 401(k) Plan The price reported is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $60.25 to $60.40, inclusive. The reporting person undertakes to provide to the staff of the Securities and Exchange Commission, the Corporation or any security holder of the Corporation, upon request, full information regarding the number of shares sold at each separate price. Reflects retirement plan contributions by the Corporation. By: Kristine L. Ouimet, pursuant to a power of attorney from Brian A. Berube 2018-06-01