the regulators who didn't see it coming
investors who are always after bigger returns
the monetary authorities who left too much cash floating around the economy for too long
traders who only ever think about themselves
banks who lent money to all and sundry
the rating agencies who gave AAA ratings to assets that weren't worth the paper they were written on
firms that took on too much debt
teachers of finance who were unable to pass on their knowledge
students of finance who failed to spend enough time burried in their books (especially the Vernimmen)
nobody, crises are inevitable
the whole capitalist system, which doesn't work