X0306 4 2021-08-04 0 0001408198 MSCI Inc. MSCI 0001416752 Pettit CD Baer MSCI INC. 7 WORLD TRADE CENTER, 250 GREENWICH ST NEW YORK NY 10007 0 1 0 0 President & COO Common Stock 2021-08-04 4 S 0 683 621.05 D 251837 D Common Stock 2021-08-04 4 S 0 550 622.36 D 251287 D Common Stock 2021-08-04 4 S 0 550 623.53 D 250737 D Common Stock 2021-08-04 4 S 0 617 624.55 D 250120 D Common Stock 2021-08-04 4 S 0 100 626.22 D 250020 D This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 2, 2020. This transaction was executed in multiple trades at prices ranging from $620.77 to $621.54. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the issuer or the security holders of the issuer full information regarding the number of shares and prices at which each transaction was effected. This transaction was executed in multiple trades at prices ranging from $622.00 to $622.99. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the issuer or the security holders of the issuer full information regarding the number of shares and prices at which each transaction was effected. This transaction was executed in multiple trades at prices ranging from $623.00 to $623.99. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the issuer or the security holders of the issuer full information regarding the number of shares and prices at which each transaction was effected. This transaction was executed in multiple trades at prices ranging from $624.16 to $625.00. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the issuer or the security holders of the issuer full information regarding the number of shares and prices at which each transaction was effected. This transaction was executed in multiple trades at prices ranging from $626.06 to $626.38. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the issuer or the security holders of the issuer full information regarding the number of shares and prices at which each transaction was effected. /s/ Cecilia Aza, attorney-in-fact 2021-08-05