[mdda]

Actually, Goldman repeatedly claimed in their defense of their actions on the Fab CDO that they had no fiduciary responsibility to their clients.

Also as a market maker, it's difficult to ignore what's going on if all the smart money is selling, and all the dumb money is buying.

FWIW, the vast majority of market-making is taking place outside of the stock exchange : End-users are at a natural disadvantage, since they can't see all the flows.