The market for credit default swaps market (a derivative on insurance on when a business defaults), for example, was enormous, exceeding the entire world economic output of $50 trillion by summer 2008. It was also poorly regulated. The world’s largest insurance and financial services company, AIG alone had credit default swaps of around $400 billion at that time. A lot of exposure with little regulation. Furthermore, many of AIGs credit default swaps were on mortgages, which of course went downhill, and so did AIG.