1.5 to 2 times. According to the query of Sina Finance Network, there is no limit on the price of bonds. The securities whose bonds are agreed by the issuer to repay the principal and interest within the time limit are 1.5 to 2 times of the fixed interest rate, so the maximum increase of interest rate bond funds is 1.5 to 2 times. Interest rate refers to the ratio of the amount of interest to the amount of borrowed funds in a certain period.