The stock purchase index can be purchased through index funds and stock index futures. Each index fund has a corresponding index, which is generally a component index (the number of stocks is fixed), such as Shanghai and Shenzhen 300, Shanghai 50, 180, etc. There are also some index funds that choose graded indexes, such as dividend index and growth index. ?

Buying an index fund is equivalent to buying a basket of stocks contained in the corresponding index. If the index goes up, it will make money, and if it goes down, it will lose money. ? There is an ETF fund in index funds, which can be purchased and redeemed like ordinary funds, and can also be traded in the day like stocks.

Extended data:

Calculation index:

When calculating the average or index of stock prices, the following four points are usually considered:

(1) sample stocks must be typical and common. Therefore, when selecting samples, factors such as industry distribution, market influence, stock grade and appropriate quantity should be considered comprehensively.

(2) The calculation method should have high adaptability, and can make corresponding adjustments or corrections to the rapidly changing stock market, so that the stock index or average value has good 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.

Baidu Encyclopedia-Stock Index