Foreign exchange is foreign currency, and buying and selling is to earn the difference! Securities investment fund is an indirect way of securities investment. By issuing fund shares, fund management companies concentrate investors' funds, which are managed by fund custodians (that is, qualified banks) and managed and used by fund managers. They engage in investment in financial instruments such as stocks and bonds, and then share the profits, and of course bear the investment risks. According to different standards, securities investment funds can be divided into different types:-according to whether fund units can be increased or redeemed, they can be divided into open-end funds and closed-end funds. Open-end funds are not listed and traded, and are generally purchased and redeemed by banks. The scale of the fund is not fixed, and the fund unit can sell it to investors at any time or buy it back at the request of investors. Closed-end funds have a fixed duration, and the fund size is fixed during the duration. Generally listed on the stock exchange, investors buy and sell fund shares through the secondary market. -According to different organizational forms, it can be divided into corporate funds and contractual funds. Securities investment funds are established by issuing fund shares to establish investment fund companies, which are usually called corporate funds; The establishment of fund managers, fund custodians and investors through fund contracts is usually called contractual funds. At present, China's securities investment funds are all contractual funds. -According to different investment risks and returns, it can be divided into growth funds, income-based funds and balanced funds. According to different investors, it can be divided into stock funds, bond funds, money market funds and futures funds.