What exactly is the difference? I see this mentioned in valuing OAS. Schweser doesn’t go into much detail.
Sort of a level I thing… maybe you should review your notes from last level. The spot rates are for zero coupon instruments, not coupon bearing treasuries.
Spot curve = Plot of yields of zero-coupon-treasury-securities and their maturities Yield curve = Plot of yields of coupon-bearing-treasury-securities and their maturities
bootstrapping an observable spot rate to build a curve