Bloomberg’s Bob Ivry and William Cohan, a Bloomberg contributing editor, talk about Goldman Sachs & Co.'s $15 billion loan from the U.S. Federal Reserve in 2008, the biggest single loan from a little-known lending program whose details have been secret until today.   Ivry and Cohan speak with Pimm Fox on Bloomberg Television's "Taking Stock." (William Cohan is a Bloomberg View columnist. The opinions expressed are his own. Source: Bloomberg)