“According to Austrian Business Cycle Theory, when a central bank slows its money printing that has fueled a manipulated stock market boom, the stock market is very vulnerable to a crash. Murray Rothbard in his book America’s Great Depression explained how it occurred before the October 1929 crash. The money supplied slowed before the October 1987 crash. It slowed before the 2008 September Financial Crisis. And it is slowing again now.”
http://www.economicpolicyjournal.com/2013/08/is-slowing-money-supply-signalling.html
