Funds are not traded in real time. Generally speaking, it is better to sell when the fund goes up and when it goes down. Investors can decide whether to trade the fund a few minutes before the closing of the trading day. The transactions of the fund before three o'clock shall be calculated according to the net value at the close of the day. At the end of the day, you can know the ups and downs of the fund by looking at the estimated net value of the fund. Funds can be bought when they fall, and sold when they rise.