Shanghai Stock Exchange reorganizes Shanghai Stock Exchange, which was released on July 199 15. The "point" is the unit, and the base date is 1990 19. The benchmark index is set at 100.
1February 2, 9921,Shanghai A-share index and Shanghai B-share index were added to reflect the respective trends of different stocks (A-share and B-share).
On June 1993 and 1 day, the Shanghai Stock Exchange's sub-indices were added, namely, industrial index, commercial index, real estate index, public utility index and comprehensive industry index, to reflect the respective trends of stocks in different industries.
So far, the Shanghai Stock Exchange Index has developed into a series of stock price indexes including comprehensive stock price index, A-share index, B-share index and sub-index.
The composite index of Shenzhen Stock Exchange includes Shenzhen Composite Index, Shenzhen A-share Index and Shenzhen B-share Index. They take all stocks, all A shares and all B shares listed in Shenzhen Stock Exchange as sample stocks, 199 1 as the base period of the composite index and A-share index, and 1992 as the base period of B-share index. The base index is set to 100, and the weighted average is based on the number of shares on the index stock calculation date. When a new share is listed, it will be included in the index calculation the day after listing. When a stock is suspended from trading, it is temporarily excluded from the calculation of the index. If a stock is suddenly suspended during trading, the final transaction price will be taken to calculate the real-time index until the market closes. The basic formula of Shenzhen Composite Index is:
Today's index = (total market value of today's index stocks ÷ total market value of index stocks on base date) × base date index.
The ring ratio formula for daily continuous calculation is as follows:
Daily real-time index = closing index of the previous day × (total market value of today's real-time index stocks ÷ adjusted total market value of the previous day's index stocks)
Among them, the total market value of today's real-time index stocks = the market price of each sample stock × the number of shares issued, while the total market value of the index stocks on the last day refers to the total value adjusted according to the changes in the share capital or sample stocks on the last day.
When the share capital structure or share list of the index share changes, the index calculation will be adjusted in a "chain" way based on the business day before the change to maintain the continuity of the index.