求助Fixed income原版书59第24题 decrease, interest, derived, whether, always

Kapie

Incoporateing convexity into the analysis of a non-callable bond's price  changes as interest rates change always results in higher bond price estimates than derived by using only the bond's duration. This is true whether interest rates increases or decrease.

答案认为这句话是正确的，求教老师，这句话表达的意思是不是：

不管利率上升或下降，不含callable option的bond在利率下降时价格的上升程度要高于free-option bond?

apf陈老师

在利率下降时free-option bond的价格上升幅度大于callable bond
在利率上升时free-option bond的价格下降幅度大于putable bond
也就是说无论价格上升还是下降free-option bond的价格变动幅度要大于含权债券