MSCI Inc. reported an insider ownership change involving Andrew C. Wiechmann in the company’s common stock, with the transaction date listed as June 10, 2026. The Form 4 was filed on June 12, 2026, and signed on Wiechmann’s behalf by Cecilia Aza as attorney-in-fact. The filing states that the transaction was carried out under a Rule 10b5-1 trading plan adopted by Wiechmann on September 3, 2025. Such plans allow corporate insiders to establish prearranged instructions for buying or selling securities at a time when they are not in possession of material nonpublic information, providing an affirmative defense against allegations of improper insider trading if the plan is followed as adopted. The document excerpt identifies the security involved as MSCI common stock but does not provide the transaction table that would normally show the specific transaction code, number of shares, price, form of ownership, or the amount beneficially owned after the transaction. As a result, the filing indicates that an insider transaction occurred on June 10, 2026, pursuant to a preexisting trading plan, but the supplied text does not disclose whether the transaction was a sale, purchase, option exercise, or other reportable change, nor does it state the share count or dollar value. The key significance is that MSCI disclosed a reportable change in Wiechmann’s beneficial ownership of company common stock, and the explanatory note frames the action as part of a previously adopted 10b5-1 plan rather than an ad hoc discretionary trade.