The Nikkei 225 is a price-weighted index of 225 major stocks listed on the Tokyo Stock Exchange Prime Market. Higher-priced constituents have more influence, making it a widely watched but distinct measure of Japanese equities.
History and development
Calculation began at the Tokyo Stock Exchange in September 1950, with values calculated back to May 1949. Responsibility moved to the Nikkei group in 1971. The index has retained its 225-stock foundation while membership and adjustment rules have evolved with Japanese industry.
References: Nikkei: index chronology
Comparing charts on this board
Place the Nikkei 225 beside TOPIX to compare two weighting approaches to Japanese stocks. The Nikkei uses constituent prices adjusted by price adjustment factors; influence is not determined simply by company market capitalization. A wide return gap versus TOPIX is a starting point for examining composition and weights.
Nearby Japanese semiconductor-stock and USD/JPY charts can help you follow individual moves alongside the index. A weaker yen does not guarantee a Nikkei rise, and strength in chip stocks does not describe every Japanese company. First inspect direction and timing, then use market reports and official releases to investigate the day's context.
Related charts: TOPIX · USD / JPY · Tokyo Electron · Advantest
Official references: Nikkei 225 · Price adjustment factor