Generally speaking, it is best to hold a bond fund for more than one year, because the income at that time will be considerable. Generally speaking, the longer the fund investment is held, the better. The research shows that the positive return probability of bond funds is proportional to the holding time, and the longer the holding time, the higher the positive return probability. Bond funds have higher returns than money funds, lower risks than mixed funds and equity funds, and lower risks than money funds and equity funds.