The securities investment of commercial banks is mainly the investment in securities, and its investment income consists of two parts: one part is interest income, including bond interest and stock dividend; The other part is the income from capital gains, that is, the income brought by the price changes in the securities market. Since the yield of bonds is fixed, as long as they are held to maturity, there will be no loss of capital gains. However, if the bonds are sold before the maturity date, they may suffer income losses due to changes in market interest rates and the relationship between supply and demand. However, the return of stocks is not fixed, and there is no maturity date. In addition to dividends, the recovery of stock investment can only be achieved by selling stocks, and as long as they are sold, there may be gains and losses, so the return of stocks is not as stable as bonds.