JPX-Nikkei Index 400 reshuffle: 45 additions, 39 deletions take effect Aug. 31, 2026
Nikkei and JPX announced the JPX-Nikkei Index 400 reshuffle, adding 45 stocks and removing 39, with changes effective Aug. 31, 2026 (JST).
The Nikkei and JPX Market Innovation & Research on Friday announced an annual revision of the JPX-Nikkei Index 400 and the JPX-Nikkei Mid and Small Cap Index. The JPX-Nikkei Index 400 will include 45 new constituents and remove 39 companies, while the Mid and Small Cap index will add 49 names and delete 43. The changes will be reflected in index calculations from Aug. 31, 2026.
Notable entrants and exits in the 400
T&D Holdings and Furukawa Electric are among the companies newly added to the JPX-Nikkei Index 400, reflecting changes in eligibility and selection criteria. Major names removed from the benchmark include KDDI and Asahi Group Holdings, which will no longer be counted in the 400 from the Aug. 31, 2026 calculation. The reshuffle alters sector composition and market weightings across the benchmark.
Mid and Small Cap index adjustments
The JPX-Nikkei Mid and Small Cap Index will see 49 additions and 43 deletions under the annual review, a net increase that mirrors movements in corporate performance and market capitalization. This parallel reshuffle is part of the same review cycle and aims to keep the mid- and small-cap benchmark aligned with current listings and financial profiles. Investors tracking smaller-cap exposures should expect portfolio turnover around the effective date.
Why additions outnumber deletions
The number of additions exceeded deletions in both indexes because some companies had previously been excluded and are now re-eligible under the review. Annual re-evaluations identify firms that meet updated criteria for profitability, governance and market liquidity, allowing those that have improved to re-enter. The net increase in constituents reflects both re-entries and the inclusion of firms that have newly satisfied the index rules.
Implications for funds and passive investors
Index changes typically trigger rebalancing flows as index-linked funds and ETFs adjust holdings to match the new constituent lists. Funds tracking the JPX-Nikkei Index 400 and the Mid and Small Cap Index will buy added stocks and sell removed ones ahead of the Aug. 31, 2026 calculation. These flows can temporarily affect share prices and trading volumes for affected companies, particularly for mid-cap names with shallower liquidity.
Timing, methodology and annual cadence
The revisions follow the indexes’ established annual review process conducted at the end of August each year, with changes implemented on the final business day of the month. The JPX-Nikkei Index 400 is designed to highlight companies that meet standards for profitability, capital efficiency and corporate governance, and constituents are screened accordingly. The regular cadence provides transparency for market participants planning rebalancing and cash-flow management.
Market reaction and sector shifts to watch
Analysts will monitor how the reshuffle shifts sector representation within the JPX-Nikkei Index 400, including any increased weightings in financials or industrials due to the new entrants. The removal of large, well-known firms such as KDDI and Asahi Group Holdings may reduce their benchmark-driven demand, while newly added names could attract inflows from index funds and passive strategies. Trading in affected stocks is likely to intensify in the run-up to the effective date.
The annual adjustments to the JPX-Nikkei Index 400 and the JPX-Nikkei Mid and Small Cap Index underscore the dynamic nature of Japan’s equity benchmarks and will be implemented in index calculations from Aug. 31, 2026.
