Central to the Japanese stock market, the Nikkei indices act as barometers of the Japanese economy. An acronym for Nihon Keizai Shimbun, the Nikkei is a group of Japanese stock market indices, the best known of which is the Nikkei 225. These indices are published by the Nihon Keizai Shimbun, one of Japan's leading financial newspapers. Launched in 1950, the Nikkei 225 is the flagship index of the Tokyo Stock Exchange. It measures the performance of 225 major companies listed on the first section of the Tokyo Stock Exchange (TSE). A price-weighted index, similar to the Dow Jones Industrial Average in the United States, the Nikkei 225 therefore gives greater weight to companies with the most expensive shares, regardless of their overall size or market capitalisation. This index covers a wide range of sectors, from technology and finance to consumer goods and energy. Other stock indices such as the Nikkei Stock Average 300, the Nikkei 500 Stock Average and the Nikkei JAPAN 1000 offer broader coverage of the Japanese economy, with 300, 500 and 1,000 company stocks listed respectively. Although it is not possible to invest in stock market indices as such (since they are merely the calculated results of a mathematical formula), there are several derivative financial products that allow you to bet on the price variations of these Japanese indices, starting with futures, options and ETFs.