Short-term holding funds are suitable for buying Class C. Class A and Class C represent different shares of an index fund. The biggest difference between the two types of shares is the different rate structure. Class a index funds charge subscription fees at the time of subscription, and generally hold them for more than two years without redemption fees; Class C index funds do not charge subscription fees at the time of subscription, nor do they charge redemption fees after long-term holding, but they charge 0.4% more sales service fees (per year) than Class A shares, but they are accrued on a daily basis. So to sum up, if the fund is held for a long time, it is best to be Class A. If it is held for a short time, it must be Class C.