One of the two major indices which tracks the performance of the Tokyo Stock Exchange (TSE), the other being the Tokyo Stock Price Index. The Nikkei Stock Average tracks the performance of the leading 225 stocks in the TSE. The components of this index are reviewed yearly. Since it is a price-weighted index, the movement of the stocks are weighted without regard to their market capitalization. Previously called the Nikkei Dow Jones Stock Average. also called Nikkei Index, Nikkei 225, and Nikkei Dow.