NO.PZ2020011303000236
问题如下：
Suppose a portfolio has an exposure of +50 to a one-basis-point increase in the five-year Treasury rate in Table13.1, an exposure of −100 to a one-basis-point increase in the ten-year Treasury rate in Table 13.1, and no other exposures. What is the portfolio’s exposure to the first two factors in Table 13.1? 
解释：
The exposure to one unit of the first factor is
50 × (−0.410) − 100 × (−0.414) = 20.9
The exposure to one unit of the second factor is
50 × 0.203 − 100 ×
(−0.193) = 29.45
题目问：假设有一个组合，当5年的treasury利率上升1bp时，exposure变成+50；10年的treasury利率上升1bp时，exposure变成-100。没有其他的exposure，根据图中前两个factor，求组合的exposure。
factor 1：
50 × (−0.410) − 100 × (−0.414) = 20.9
factor 2：
50 × 0.203 − 100 × (−0.193) = 29.45
老师好，5年期债券，利率上升一个bp，敞口增加50，利率减少0.41%时，0.41%是41个bp，敞口不是应该减少41*50=2050吗？没看懂为什么是20.5？
