SMBC Nikko Securities estimates in a July 3 report that if Japan Exchange Group
raises Kioxia’s free-float from 15% to 50%, the company’s TOPIX weight would
more than double to 2.678% at the October rebalancing, triggering roughly ¥3tn
(~$18.5bn) of passive buying. The needed purchases would be roughly equivalent
to the stock’s 30‑day ADV. SMBC calls the inflow size unprecedented and says
implementation may be phased to limit market impact. Additional passive demand
could support Kioxia shares, which had rallied about 940% to last month’s peak
and have since pulled back roughly 25% amid AI valuation concerns.