The stock market is like an addict hooked on QE. Whenever there is a hint of it slowing down, stock price tumbles.
Quantitative Easing (or pumping money into the society) is part of the monetary policy which regulate how much money should be circulating in the country. The Federal Reserve System, operated independently from the government, controls monetary policies. The government, on the other hand, controls the fiscal policies which is the combined governmental budgets: governmental payroll, social welfare, defense, education, roads and bridges, park and recreation, etc.
The Federal Reserve pumps money by buying bonds or lowering the lending interest rate. It prints new money to pay for them. The funny thing is, the government, particularly the administration branch, cannot get those new monies. This is called the separation of monetary and fiscal policies. This works beautifully, until we have the economical crisis of late.
The government, due to the economy, found itself in heavy debt and must trim back spending. The Fed, seeing the same the economy, decided to stimulate by pumping more money out. Because of this separation of policies, the government cannot get those monies to build infra-structures — roads, bridges, information super-highway, education, etc. — to get the economy back up. All those monies pumped out went to somewhere in the society, but not to where it really matter for the long-term competitiveness of the country.
This is why most governments in the world envy China.