If you want to make a fixed investment, it is recommended to engage in stock funds, bond funds and mixed funds. Their income is higher than that of the money fund, but there are risks, and the money fund has almost no risk.
Personally, I don't think it is necessary to make a fixed investment. Unless you don't spend money on self-control. My approach is to buy cash from Huaxia to increase income when I have spare money, as well as bond funds. According to my financial knowledge, the risk size: stock >; Bonds. You can go to official website to find historical income data of various funds and compare them yourself.