OAS relative to sector benchmark

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

Why wouldn’t it be fairly valued?


Is it b/c the benchmark has lower risk?

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)

That is in the CFAI text?

p 264 Book 5 bottom paragraph