Collateralized debt obligations fueled financial crisis

A report by ProPublica's Jake Bernstein and Jesse Eisinger "shows for the first time the extent to which banks &#8212 primarily Merrill Lynch, but also Citigroup, UBS and others &#8212 bought their own products and cranked up an assembly line that otherwise should have flagged."  These banks dealt in collateralized debt obligations, or CDOs.  A CDO is a collections of mortgage bonds, and each includes risky investments.  The banks would then create new CDOs to sell the risky pieces creating false demand for these toxic assets.