Could T-bond futures be used to hedge spread risk? I don’t think so. Spread risk is the risk of the mortgage security’s yield spread over the corresponding T-bond widening.
i think you’re correct. the mortgage security’s spread is referenced against Ts
T-bond usually hedge a paralle shift in the yield curve. Plus, I think in the material it says that for MBS, spread risk is not one of the risk you want to hedge (that is where the gain is from)