Best travel 2015 lonely planet for O., 1982); Nigeria, CIA World Factbook (2002). ELIZABETH PURDY, PH.D. INDEPENDENT SCHOLAR Nikkei THE LONGEST RUNNING stock price index in JAPAN’s history, the Nikkei Stock Average (Nikkei) has been calculated continuously since September 7, 1950, when the newly reopened Tokyo Stock Exchange (TSE) began using the DOW JONES method to calculate the stock-price average. This is the method still in use today and the Nikkei has grown to become Japan’s leading and most widely quoted index of stock market activity. Similar to the Dow Jones Industrial Average, the Nikkei is used to calculate the average stock price of 225 leading stock issues traded in the first section of the TSE (medium to large capitalization stocks). Best travel 2015 lonely planet 2016.