What is the name of the main stock market index in Japan?

Japan’s main stock-market index is commonly identified as the Nikkei 225.

The Nikkei 225, also called the Nikkei Stock Average, tracks 225 prominent companies listed on the Prime Market of the Tokyo Stock Exchange. It is price-weighted, meaning companies with higher share prices exert more influence on the index than companies with lower-priced shares, regardless of market capitalization.

The index began in 1950, although its historical series is calculated back to 1949. It includes major Japanese names such as Toyota, Sony, Fast Retailing, and SoftBank Group, and it is widely followed as a headline gauge of Japanese equities and investor sentiment.

A frequent mix-up is TOPIX, the Tokyo Price Index. TOPIX is broader and free-float market-capitalization-weighted, so it represents the Tokyo market differently. Both are important Japanese benchmarks, but the Nikkei 225 is the internationally familiar headline index and the intended answer in most general-knowledge quizzes. The FTSE 100, KOSPI, and Hang Seng Index instead represent the United Kingdom, South Korea, and Hong Kong.