Pure debt fund, investment target: do not participate in stock investment, only invest in fixed-income financial instruments. Asset allocation: high-yield bond portfolio. Product features: pure debt. Risk characteristics: low risk. It is not difficult to see that the biggest difference between the three bond funds lies in the different investment scope. Pure bond funds can invest in limited wealth management products and can only invest in fixed-income wealth management products. On this basis, the primary debt base can participate in the investment of new shares in the primary market, and the secondary debt base expands the investment scope on the basis of the primary debt base, so it can properly participate in the stock trading in the secondary market. Among the three, the secondary debt base has the highest risk, but the expected return is also the highest; It is difficult to make a big breakthrough in the income of pure debt funds, but its advantage lies in its stable income and low risk. Knowing the characteristics of the three bond funds, it is not difficult to find that the pure debt fund and the primary debt base are more suitable for conservative investors who pursue stable income, while the secondary debt base provides a more radical choice for investors who pursue low risk. The secondary debt base can be both offensive and defensive in the volatile market because of its configuration characteristics. On the basis of bond market returns, the probability of seizing the opportunity of band stock market to obtain excess returns will increase.