Japan Exchange Group announced that the Tokyo Stock Price Index (TOPIX) will undergo a major restructuring starting at the end of October, reducing its constituent count by approximately 40% to 986 companies. The adjustment marks a significant shift in how Japan's benchmark index is composed. Under the new rules, inclusion in TOPIX will depend on stock trading activity and free-float market capitalization rather than listing status on the Prime Market. Previously, nearly all companies listed on the former First Section were automatically included, but the updated criteria aim to ensure constituents meet specific liquidity and market value thresholds.