I don't think Goldman will be doing too many of those back room Abacus deals anymore. Even John Paulson who made $billions shorting mortgages has taken the rebuilding side of the economic process now. The big banks in particular have been experiencing $billions in fines by regulators world wide. Some weren't even real banks but investment banking firms operating in the shadows of commercial banks. Investment banks primarily depend on free markets to access capital for operations and building businesses while bank holding companies are able to access public deposits through savings, for example with FDIC backstop. When markets lose confidence, pure investment banking operations experience huge lack of confidence from investors whom those shadow banks depend on for accessing capital funding.