Shanghai Composite, STAR Composite Indexes Set for Revision, Effective Tomorrow

On September 24, the Shanghai Stock Exchange published an announcement on revising the calculation methodology for the SSE Composite Index series. The indexes slated for revision include the SSE Composite Index, SSE A-Share Index, SSE Free-Float Index, and STAR Composite Index. The methodology revisions for these indexes and their derivative indexes will take effect on October 26, 2026. According to the announcement, the Shanghai Stock Exchange and China Securities Index Co. decided to revise parts of the SSE Composite Index series methodology, including: (1) adding a rule capping the weight of any single constituent at 15%; and (2) adjusting the removal timing for risk-warning securities from "the next trading day after the second Friday of the month following the risk-warning implementation date" to "the next trading day after the second Friday of the month following the risk-warning announcement date." All other parts of the index methodology remain unchanged.