From Claus Vogt, Weiss Research Inc:
"In 1930, the market rose roughly 50 percent from its 1929 crash low thus recouping half of the preceding losses. This monster rally led many contemporary economists, politicians and financial market experts to reason that the worst was over. But it was not to be ... The Great Depression had barely started, and the stock market suffered losses of another 85 percent measured from this interim high of 1930.
How does the current rally compare to this frightening potential predecessor? There is a scary similarity between the 1930 rally and 2009's. Well, from the March low the S&P 500 has soared 69 percent in nine months. In doing so it recouped a bit more than 50 percent of its former losses. But it's still 27 percent below its all time high of October 2007. Yes, the market rallied strongly in 2009. But it did the same thing in 1930. History then tells us that the current stock market rally is not sufficient enough to reason that the worst is over."