Generally speaking, when the net value of the fund falls, choose the fund to make a fixed investment, and spread the cost of holding the position and spread the risk through continuous buying in the process of falling. When the fund rebounds, it will reach the smile curve effect, and the fixed investment in the rising process will not only increase the cost of investors' positions, but also increase the risks. Therefore, investors can suspend the fixed investment operation when the fund rises.

At the same time, in the process of fixed investment, investors do not need to set a stop loss position, but can set a take profit position to realize part of the profit.