Securities investment fund is a kind of collective securities investment model with * * * returns and * * risks, that is, investors' funds are pooled by issuing fund shares, managed by fund custodians, managed and used by fund managers, and invested in financial instruments such as stocks and bonds. ? Stock is a certificate issued by a joint-stock company to prove the shares held by shareholders, and it is the form of company shares. Investors become the owners of the issuing company by buying shares, get operating income according to their shareholding shares and participate in major decision-making voting. ? Bonds refer to securities issued in accordance with legal procedures and agreed to repay the principal and interest within a certain period of time. Its characteristics are fixed income and less risk. ? Funds, stocks and bonds are all securities, and investments in them are all securities investments. The division of fund shares is similar to that of stocks: stocks are divided into "shares" and their total assets are calculated; Fund assets are divided into several "fund units", and investors share the value-added income of the fund according to the share of holding fund units. Contractual closed-end funds are similar to bonds, and the investment will be recovered once the contract expires. In addition, stocks and bonds are the investment targets of securities investment funds, and there are stock funds and bond funds specializing in stocks and bonds abroad.