Fund trading is a circulation and transfer activity that takes funds as the buying and selling object and bears the risks and benefits on its own. Depending on whether fund units can be added or redeemed, they can be divided into open-end funds and closed-end funds. Open-end funds are not listed for trading (it depends on the situation). They are purchased and redeemed through banks, securities firms, and fund companies. The fund size is not fixed; closed-end funds have a fixed duration and are generally listed and traded on securities exchanges. Investors pass Fund units are bought and sold in the secondary market. According to the different investment objects, they can be divided into stock funds, bond funds, and currency. The principle of unknown price is that the fund will announce the net value of the fund on that day after the close of each trading day, so it is traded at an unknown price during transactions. The principle of amount subscription and share redemption means that when purchasing, apply based on amount, and the fund company will confirm the purchased shares based on the fund net value on day T; when redemption is applied based on shares, the fund company will confirm the redemption fee amount based on the fund net value on day T. Market funds, Futures funds, etc. Buying includes subscription, subscription, fixed investment, etc.; selling includes redemption, liquidation, etc.