The purpose of copying the index is to track the rise and fall of the index as error-free as possible.

The meaning of copying is passive tracking.

For example, the CSI 300 Index consists of 300 stocks in the Shanghai and Shenzhen Stock Exchanges, which are leaders in various industries.

But each stock has different weights because of its different total share capital. To put it simply, if the inflation of a large company and a small company rises by the same amount, the large company must have a greater impact on the index. .

How to copy an index? That is, the fund purchases 300 stocks and allocates them in proportion to the different weights of these 300 stocks. Finally, a rule was reached that the fund would rise or fall as much as the index rose or fell. But it is difficult to do it completely without errors, there will always be some differences.