Look at the price-earnings ratio of the benchmark index. It is safer to buy when the price-earnings ratio is lower than the long-term average price-earnings ratio and sell when the price-earnings ratio is higher than the long-term average price-earnings ratio; Determine the buying opportunity according to the historical percentile of P/E ratio/P/B ratio.

Observe the trend of the fund. For excellent funds, if you don't grasp the opportunity of bargain-hunting, you can choose to buy at the continuous rising stage of the fund, buy low and sell high.

It is difficult for the fund market to have an absolute "best trading opportunity". Even if there is, it may not be captured by ordinary investors. Therefore, fund transactions need to be cautious and not blindly follow suit.