Here is an alphabet-soup of regulatory agencies that let MF Global, a financial services company that specialized in futures-trading, engage in much, too much, risk: SEC, CME, CFTC and FINRA. On one level, regulators will never be able to stop practitioners from making risky or simply bad decisions; a business system populated only by firms above average is by definition impossible. As long as their managers have any freedom of movement at all, some firms, including some in the financial sector, will inevitably fail. The question I want to pose is whether this means that firms too big to fail (TBTF) should be allowed to exist at all. In short, although MF Global itself was not TBTF, the risk Corzine (who had been chairman of Goldman Sachs) permitted suggests that human nature might be insufficiently disposed to support mammoth concentrations of private capital whose fall could mean the collapse of the financial system itself. Ultimately, I suppose, human nature can only go so far, organizationally speaking.
The full essay is at "The Downfall of MF Global."