NO.PZ2023052301000020
问题如下：
A non-callable, fixed-coupon bond has a price of 106.0625 and a YTM of 2.8%. If the YTM were to increase instantaneously by 80 bps, the price of the bond would decrease by 11%. If the YTM were to decrease instantaneously by 80 bps, the price of the bond would increase by:
选项：
A.less than 11%.
exactly 11%.
more than 11%.
解释：
C is correct. The absolute amount of the price increase would be more than the absolute amount of the price decrease for the same absolute change in YTM because of the convex relationship between bond price and yield.
A is incorrect because of the positive convex relationship between bond price and yield. For a given level of yield change, the price rise for that given amount of yield decrease will be larger than the price decline for that amount of yield increase.
B is incorrect because the relationship between bond price and yield is not linear.
回到本题： If the YTM were to increase instantaneously by 80 bps, the price of the bond would decrease by 11%. 现在利率上升80bp，带来价格下跌了11%，价格的跌幅更小。小于利率下降80bp带来的价格涨幅，所以价格涨幅应该大于11%，选C。
----以上是助教老师在其他问题下的回复，
我的问题如下：
- 涨多跌少也不是一个量纲，怎么比较的呢。 一个涨了用basis point衡量 一个是跌了11% ，看绝对值是价格的变动幅度更大，为什么老师解答说价格跌幅更小。
- 按照老师解释的逻辑， 是怎么从“价格跌幅小于80bp带来的价格涨幅”推到“价格涨幅应该大于11%”的结论
