1, unable to obtain excess returns: index funds passively follow index returns and do not take exceeding market returns as the investment goal, which will make investors lose time costs.

2. The fund fluctuation is not particularly large: the fixed investment fund obtains the average cost and income, which is more suitable for the fund with large fluctuation, and the stock fund and partial stock fund are more suitable.

3. Funds lead the gains but don't resist the declines: Most index funds fall to varying degrees when the stock market falls, which will reduce investors' returns.