The Nikkei Stock Index 300 is a market value-weighted index to represent overall Japanese market with smaller number of stocks.
300 issues (common domestic stocks) selected from the Prime Market of the Tokyo Stock Exchange.
The components are reviewed at the beginning of October by the Annual Review to keep the representativeness of the market. The Annual Review is conducted based on increase in market value for the past 3 years and its contribution for each 36 industrial sectors. In case of delisting of the index constituents due to a merger or bankruptcy, stocks are added by the Extraordinary Replacement, and the number of components remains at 300.
The index is a market value-weighted index. The index is calculated by dividing the current total market value by “base market value”. Base market value is adjusted to maintain continuity in the index when the market value of constituents changes for non-market reasons.
The index has been calculated since October 8, 1993. The index has a base value of 100 as of October 1, 1982 and has been calculated at 5-second intervals during the trading hours of the Tokyo Stock Exchange.