Thanks for the reply Kzg.
I just wondered as Basis Risk is the risk due to change in risk free rate, dividend etc changing between spot and futures, when you are estimating beta by a historical regression between spot and futures, wouldnt you pick up these risk free rate and dividend noise etc in the regression and account for it in the beta. So the beta (which tells you how much the spot will change if the futures changes by x) would implicitly account for Basis as well. I am not sure
Anyway, for the PRM exam, i’ll just assume, beta <>1 captures the non-unity move between spot and futures, and Basis is due to the change in risk free, dividends etc.