The fixed investment of the fund is also called the smile curve. If you want to achieve the most beautiful smile curve, then it is best to let the fund go through a bull-bear cycle, each bull-bear cycle lasts about 3-6 years. The best choice of fixed investment is to invest in a bear market for a long time to dilute the investment cost, and then redeem the fixed investment fund when the bull market returns considerable, and then invest in the next bear market to achieve the best investment income effect.