Stock Index: It is the index of the stock market
Shanghai Composite Index:
Shanghai Composite Index is compiled by the Shanghai Stock Exchange and listed on the Shanghai Stock Exchange All stocks are included in the calculation range, and the weighted comprehensive stock price index is weighted by the issuance amount. The index uses December 19, 1990 as the base day, and the base day index is set at 100 points. It has been released since July 15, 1991. The index reflects the stock price trends of all A shares and all B shares listed on the Shanghai Stock Exchange. Its calculation method is roughly the same as that of the Shenzhen Composite Index, but the difference lies in the treatment of new stocks.
For the calculation of the Shanghai Composite Index, when a new stock is listed, it will be included in the calculation scope one month later.
Shenzhen Composite Index:
The Shenzhen Composite Index is a stock price index compiled and published by the Shenzhen Stock Exchange since April 3, 1991. The index stipulates that in 1991 April 3rd of the year is the base period, and the base period index is 100 points. The comprehensive index is a weighted comprehensive stock price index based on all stocks listed on the Shenzhen Stock Exchange and with issuance as the weight. Its basic calculation formula is: Intraday Comprehensive Index = (Total market value of index stocks on the current day / Index stocks on the base day (total market capitalization
After the new stock is listed, the "total market value of the constituent stocks on the base day" = the original total market value of the constituent stocks on the base day + the number of new shares issued × the closing price on the first day of listing
When a certain component When trading of a stock is suspended, it will be temporarily excluded from the index calculation. If a component stock is suddenly suspended during trading, its latest transaction price will be used to calculate the real-time index, and the necessary adjustments will not be made until after the market closes. For ex-dividends, the index remains unchanged because the total market capitalization remains unchanged. Because the Shenzhen Stock Exchange Index is compiled using an advanced weighted index method, with extensive sampling and strong representativeness, it not only has long-term comparability, but also can accurately reflect the general trend of stock price movements.
Stocks rise and fall every day. When rising stocks account for a larger proportion of the total weight, the market will rise, and vice versa. In addition to the rise or fall of most all stocks, another important reason that affects the rise or fall of the market index is the stocks with larger weights, that is, companies with larger total capital stock. For example: 600028 Sinopec accounts for 10.92% of the Shanghai Composite Index. Its rise and fall will affect the direction of the Shanghai Composite Index.