share index share index(stock market index) An index formed by selecting a number of prominent shares traded on a stock exchange and comparing the value of these shares with their value on a stated date in the base year. The daily value of the index may be weighted according to the prices of the shares traded or (more commonly) by the market capitalization of the company. SeeDow Jones Industrial Average; FTSE Indexes; Hang Seng Index; Nikkei Stock Average. |