Index c refers to the class c share of index funds. If the index fund is followed by a, it represents the class A share of the fund. The difference between Class A shares and Class C shares is that the fund code is different, the income is different, and the handling fee is different, mainly the handling fee is different.

Class A shares are charged subscription, subscription and redemption fees, excluding sales service fees. Class A shares (held for more than 30 days) do not charge subscription and subscription fees, but charge sales service fees. Class A shares and Class A shares charge the same custody fee and management fee.