"A Simple Theory of the Financial Crisis; or Why Fischer Black Still Matters," by T. Cowen, FAJ Vol 65(3) (2009) 17-20.

The individuals who were running large financial institutions had an opportunity to pursue strategies that resembled, in terms of their reward structures, going short on extreme market volatility. Those strategies paid off for years, but ended in disastor. Until the volatility actually arrives, this trading position will appear to yield supernormal profits, and indeed, the financial sector was enormously profitable until the asset pricing bubble burst.