What do you mean by "Shenzhen Stock Exchange" and "Shanghai Stock Exchange", which are often mentioned in the stock market, going up or down, hundreds of points and thousands of points? What is the co

What do you mean by "Shenzhen Stock Exchange" and "Shanghai Stock Exchange", which are often mentioned in the stock market, going up or down, hundreds of points and thousands of points? What is the concept? the stock index is the stock price index. It is a reference indicator compiled by a stock exchange or a financial service institution to indicate the changes in the stock market. Due to the volatility of stock prices, investors are bound to face market price risks. It is easy for investors to understand the price changes of a specific stock, but it is neither easy nor annoying to understand the price changes of a variety of stocks one by one. In order to adapt to this situation and need, some financial service institutions make use of their professional knowledge and the advantages of being familiar with the market to compile stock price indexes and publish them publicly as indicators of market price changes. Based on this, investors can test the effect of their investment and use it to predict the trend of the stock market. At the same time, the press, company bosses and even political leaders also use this as a reference index to observe and predict the social, political and economic development situation.

this stock index is the average price that shows the changes of the stock market. The stock index is usually compiled on the basis of a certain month in a certain year, taking the stock price of this base period as 1, and comparing the stock price of subsequent periods with the base period price to calculate the percentage of rise and fall, which is the stock index of this period. Investors can judge the changing trend of stock prices according to the rise and fall of the index. And in order to reflect the trend of the stock market to investors in real time, almost all stock markets publish the stock price index at the same time as the stock price changes.

to calculate the stock index, we should consider three factors: first, sampling, that is, extracting a few representative constituent stocks from many stocks; The second is weighted, weighted average by unit price or total value, or unweighted average; The third is the calculation program, which calculates the arithmetic average, geometric average, or takes into account the price and total value.

due to the variety of listed stocks, it is arduous and complicated to calculate the average price or index of all listed stocks, so people often choose several representative sample stocks from listed stocks and calculate the average price or index of these sample stocks. Used to indicate the general trend and fluctuation range of stock prices in the whole market. When calculating the stock price average or index, the following four points are often considered:

(1) Sample stocks must be typical and common. Therefore, the industry distribution, market influence, stock grade, appropriate quantity and other factors should be comprehensively considered when selecting sample correspondence.

(2) The calculation method should be highly adaptable, and can make corresponding adjustments or corrections to the ever-changing stock market, so that the stock index or average has better sensitivity.

(3) There should be scientific calculation basis and means. The calculation basis must be unified, generally based on the closing price, but with the increase of calculation frequency, some are calculated at the hourly price or even shorter time.

(4) The base period should be well balanced and representative.