I’ve looked at previous posts, and I’m even more confused now.
I know for certain that if the yield curve is flat then:
Nominal = Z spread
if it’s an option free bond then:
OAS = Z spread
what I’m confused is:
callable bonds have Z-spreads > OAS?
Can someone please help? is this correct?
Yes, that is correct, for a callable bond:
z-spread = OAS + cost of call option
so z-spread is greater than OAS.
Yes Z > OAS Callable bond… Means option cost is positive ( Z-spread - OAS) > 0
Z-Spread< OAS Putable bond… Meand Option cost is negative ( Z-Spread- OAS) < 0
***think about it this way… Price of a callable bond equals Price of an Option free bond + ( the negative option cost)… SO its actually: Price of option freebond - option cost… The Value to the holder of a callable bond will be less than the one of the option free bond (so you will require a higuer yield to hold it)…Same logic with the putable bond…Hope thats clear.
i had some trouble with it too, but the way i now understand it is:
a normal bond of a certain credit quality/maturity etc has a certain z sprea “x”
the same exact bond that is callable has the same z spread plus an OAS to pay for the call…
am i correct here?