A huge part of the financial crisis of 2008 was an out of control derivatives market. Derivatives are basically bets that corporations make on whether the markets will go up or down. It's WAY more complicated than that, but that's the best I can do in one sentence. In the late 90's a financial regulator in the Clinton administration tried to impose regulations on over the counter derivatives, and here's what happened:
The scary fact is that the Dodd-Frank bill didn't include any regulation of the derivatives market. So basically, there is nothing in place to prevent the financial collapse of 2008 from happening again just as easily. Gah!