Graded funds, also known as "structured funds", refer to the types of funds that show two-level (or multi-level) risk-return performance with a certain differentiated fund share by decomposing the fund income or net assets under a portfolio. Its main feature is to divide the fund products into two or more types of shares and give different income distribution respectively. The sum of the product of the net value and proportion of each sub-fund of the graded fund is equal to the net value of the parent fund. For example, the net share value of the parent fund split into two types of shares = the net share value of the A type sub-base of XA share%+the net share value of the B type sub-base of %+XB share%. A shares are relatively stable and have low risks. Generally, there are agreed income and regular dividends. B shares adopt leverage mechanism, which is more radical, riskier and more profitable.