OAS
The extra yield (in basis points) a bond pays above Treasuries, adjusted for embedded options \u2014 strips out call/prepayment option value to isolate the pure credit and liquidity premium. Wider spread = more credit risk being priced in.
Why it matters
For callable bonds, the nominal spread overstates the actual credit risk because part of the yield compensates investors for the call option the issuer holds. OAS strips that out, giving a cleaner comparison across bonds with different embedded options.
How to read it
Compare OAS to historical levels and sector peers. A widening OAS suggests deteriorating credit perception. OAS is most critical for mortgage-backed securities where prepayment optionality is significant.
Lessons that use this term
Related terms
10Y Treasury · Altman Z-Score · Asset Sensitivity · Basel III · Bond ETF · Bretton Woods
Open this term in the app → — no account needed; browse the full glossary while you research.