OAS relative to sector benchmark

CFA Level II
#1

If the OAS is 0 relative to your sector benchmark, why is the issue overpriced?

Why wouldn’t it be fairly valued?

Thanks.

#2

Is it b/c the benchmark has lower risk?

#3

The assumption is always that the benchmark you are using has higher credit quality than the security (not sure of the page, but its CFAI text)

#4

That is in the CFAI text?

#5

p 264 Book 5 bottom paragraph