The Shanghai Composite Index, the full name of which is "Stock Price Composite Index of Securities Companies and Stock Exchanges", is a statistical index widely used at home and abroad to reflect the overall economic trend of Shanghai stock market. The Shanghai Composite Index was compiled by Shanghai Stock Exchange and published on July 199 1. The reference number of Shanghai Stock Exchange is "Dian" and the benchmark date is 1990 12 19. The base date is 100. With the continuous innovation and development of China and Shanghai as stock markets, on February 2 1, 1, 992, Shanghai A-share market index and Shanghai B-share index were added to reflect the respective trends of stocks (A-share and B-share) affected by different enterprises. In June 1993 and 1, the sub-indices of Shanghai Stock Exchange, namely industrial index, commercial index, industrial index, public utility index and comprehensive industrial index, were added to reflect the respective trends of stocks in different industries. Up to now, the research of Shanghai Stock Exchange Index has begun to develop students into a series of stock price indexes, including enterprise comprehensive stock price index, A-share index, B-share index and classification index.