The full extent of the futures brokerage's big bets on the recovery of European debt only emerged in recent weeks, as MF Global revealed in public filings that it had a long position of $6.3 billion in short-duration European sovereign debt -- roughly five times the firm's book value, or net worth.
There's some whining about regulators in the article, but basically...if you can't possibly make your margin calls, then you're going to get fucked eventually.