First, there are many reasons for the differentiation of fund performance over a period of time. It may be that the fund manager is well managed, or the market trend is very good, or it may be that investors have taken high risks that they should not take, so it is necessary to compare the performance of a single fund with multiple standards in order to judge the performance of the fund fairly.

First of all, the fund return rate should be compared with the trend of the stock market. If a fund performs better than the market index most of the time, investors can say that the management of this fund is effective, and the fund management company that manages this fund has excellent research and investment capabilities.

Second, we should compare the income of the fund with that of similar funds. If the fund performance exceeds other similar funds for a long time, it shows that the fund manager has excellent management ability. What needs to be pointed out here is that different types of funds cannot be compared with each other, such as stock funds and hybrid funds, and hybrid funds and bond funds cannot be compared with each other, because different types of funds have different risk-return ratios and different position allocation and operation methods. Generally speaking, the higher the risk, the more radical the operation method, and the higher the corresponding return on investment.

Third, we should compare the fund's rate of return with the expected rate of return, and see whether the fund's performance meets investors' expectations according to the fund's investment principles and the fund manager's operating philosophy. When the performance of the fund is far from the expectation, investors should look back to see if the fund manager has violated the investment principles and concepts promised in the fund contract and unnecessarily increased the investment risk of the fund.

Fourth, we should compare the fund income with historical performance. Only stable performance is the real performance, occasional success may be just luck, and occasional failure may be only temporary. Investors should comprehensively judge the performance of funds from a long-term perspective.

Investors can also rely on the judgment of some experts. Professional evaluation reports usually provide some special evaluation indicators, such as Sharp ratio, Treno ratio and so on. These risk-adjusted performance indicators can compare the performance of different funds and are good indicators to measure the management ability of fund managers.