The 2008 financial crisis was caused by the collapse of the sub-prime mortgage market in the United States, which spread globally. Major financial institutions like Lehman Brothers failed or were bailed out by governments. Complex financial products like collateralized debt obligations (CDOs) spread risk in opaque ways and exacerbated the crisis. The crisis had wide-ranging aftermath including government bailouts, investigations into its causes, and protests against Wall Street like the Occupy Wall Street movement.