NO.PZ202112010200001903
问题如下：
Which bond rating category offers the highest expected excess return if spreads instantaneously rise 10% across all ratings categories?
选项：
A.A rated bond category
BBB rated bond category
BB rated bond category
解释：
A is correct. If spreads rise 10% across all ratings categories, we can use
E[ExcessSpread] ≈ Spread0 –(EffSpreadDur × ΔSpread) – (POD × LGD) to solve
for expected excess spread as follows:
这里的spread上升百分之十，为什么不是直接将delta spread作为10%来计算，而是将10%*每个之前的spread作为delta spread？
