Index fund callback is the decline of index fund, also called index fund retracement. It is normal for index funds to follow the index, the index falls, and the index funds follow the callback. As long as the index valuation is not high, investors don't have to worry, but they can hold the growth.

Mbth callback refers to the phenomenon that in the upward trend of prices, prices temporarily fall because they rise too fast and are suppressed by sellers. The callback range is less than the increase range, and the upward trend will resume after the callback.