my impression - memory - was F and F written paper got hurt but that was NOT the real cited problem
Re Derivative Contracts --- are you referring to CDO? That would be the MBS paper that F and F create and sell (Collateralized Debt Obligation - or a bond (here Mortgage) with collateral) ?
or are you talking about the massive - so called market - of CDS -- which are synthetic BETS?
I imagine that F and F was not long or short a lot - if at all in the CRAZY CDS market that was 90% or more of the AIG collapse (the only "player" that was always - 100% - on the long side of these counter party BETS)
My sense is simpler ---- F and F - like a consumer or pension or ? - bought CDO - MBS that were built by private banks ----- Private Label MBS ---- for the high interest they provided the holder - and these PLMBS "bonds - paper" went down and down and then down in value = especially if you bought the wrong tranches - (some went to zero and never came back)