X0306 4 2021-02-05 0 0001408198 MSCI Inc. MSCI 0001769683 Wiechmann Andrew C. MSCI INC. 7 WORLD TRADE CENTER, 250 GREENWICH ST. NEW YORK NY 10007 0 1 0 0 Chief Financial Officer Common Stock 2021-02-05 4 A 0 4296 0.00 A 19417 D Common Stock 2021-02-05 4 F 0 2121 429.81 D 17296 D Common Stock 2021-02-06 4 F 0 196 429.81 D 17100 D Common Stock 2021-02-06 4 F 0 91 429.81 D 17009 D Common Stock 2021-02-07 4 F 0 181 429.81 D 16828 D Represents the number of shares of common stock issued following the vesting and conversion of performance stock units ("PSUs") granted to the reporting person on February 6, 2018, upon certification by the Compensation & Talent Management Committee on February 5, 2021 of the achievement of the performance metric for the performance period from February 6, 2018 to February 4, 2021. Represents shares reacquired by MSCI Inc. to satisfy tax withholding obligations in connection with the vesting and conversion to shares of 4,296 PSUs granted on February 6, 2018 (includes the performance adjustment as described above). Represents shares reacquired by MSCI Inc. to satisfy tax withholding obligations in connection with the vesting and conversion to shares of the third tranche of 368 restricted stock units granted on February 6, 2018. Represents shares reacquired by MSCI Inc. to satisfy tax withholding obligations in connection with the vesting and conversion to shares of the first tranche of 170 restricted stock units granted on February 6, 2020. Represents shares reacquired by MSCI Inc. to satisfy tax withholding obligations in connection with the vesting and conversion to shares of the second tranche of 339 restricted stock units granted on February 7, 2019. /s/ Cecilia Aza, attorney-in-fact 2021-02-09