Dividing funds into two categories, A and B, is called graded funds, and most of them distinguish the identity of investors, the starting point of subscription amount, rates, yields, trading methods and so on.

For example, some bond funds are divided into AB, Class A funds charge subscription and redemption fees, while Class B funds have no subscription and redemption fees, but they have sales service fees. This interest rate arrangement has different attractions for different investors. Investors who buy Class A funds are mostly long-term holders, because in the long run, Class A funds that do not charge sales service fees have higher net worth. As long as it is held for a long time, the net income can offset the subscription fee and redemption fee. For short-term holders, without subscription or redemption fees, they can get more realistic income, even if they lose some sales and service fees on the net value, it is cost-effective.