TOPIX is scheduled for reform in October 2026. The article explains the three roles of the index, which has a history spanning more than 50 years, and the fact that assets tracking it have reached approximately ¥160 trillion.
TOPIX is scheduled for reform in October 2026. The article explains the index's basic roles, structure and use.
TOPIX uses 4 January 1968 as its base date and began calculation on 1 July 1969. Free-float shares have been introduced gradually since 2005.
TOPIX has three roles: as an economic thermometer, as a yardstick for evaluating investment performance, and as an investment vehicle through ETFs, mutual funds and other products. Assets tracking the index are estimated at approximately ¥160 trillion.
TOPIX is weighted by market capitalization, so stocks with larger market capitalizations have a greater impact on index weightings. Compared with the Nikkei 225, the index tends to be less concentrated in its largest constituents.