Subject: Re: Check Capital Management BRK Options Stragegies
Alpha = abnormal returns in excess of expected market returns (beta, short for beta * index returns).

Put call parity:
Bond + call = stock + put
i.e.
Bond - put = stock - call
Which is shorthand for, holding a risk free bond and selling a put on a stock has tge same risks and return as holding that stock and selling calls on it with the same terms as the put (strike price and date).

So no, a bond index alone is not at all a valid benchmark to judge Check Capital's performance. They used it to make themselves look better than their actual performance warrants.