Because the bonds issued earlier are generally issued close to the bank's time deposit income, the yield of bonds to be issued in the future will decrease after the bank loan interest rate is lowered, which means that the price of bonds issued before will increase to increase this appreciation space, and after the bank loan interest rate is lowered, the deposits will also decrease, so the money deposited in the bank will flow into the bond market in large quantities, which is why the bond price will be raised when the bank loan interest rate is lowered.