The worst stock market crashes in U.S. history have come during the month of October.  There is just something about this time of the year that seems to be conducive to financial panic.  For example, on October 28th, 1929 the biggest stock market crash in U.S. history up until that time helped usher in the Great Depression of the 1930s.  And the largest percentage crash in the history of the Dow Jones Industrial Average by a very wide margin happened on October 19th, 1987.  Overall, 9 of the 16 largest single day percentage crashes that we have ever seen happened during the month of October.  Of course that does not mean that something will happen this October, but after what we just witnessed in September we should all be on alert.

Clearly, there is a tremendous amount of momentum toward the downside right now.  As you can see from the chart below, all of the gains for the Dow since the end of the 2013 calendar year have already been wiped out…

And as I wrote about just the other day, last quarter we witnessed the loss of what we just witnessed in September in “paper wealth” on stock markets all over the planet.  The following comes from Justin Spittler…

The S&P 500 fell 8%… and so did the Dow and the NASDAQ. It was the worst quarter for U.S. stocks since 2011.

Stocks around the world dropped too. The MSCI All-Country World Index, which tracks 85% of global stocks, also had its worst quarter since 2011. The STOXX Europe 600 Index, which tracks 600 of Europe's largest companies, fell 10%. It was the worst quarter for European stocks since 2011 as well.

China's Shanghai Composite fell 28% last quarter, its largest quarterly decline in seven years. The MSCI Emerging Markets Index fell 19%. It was the worst quarterly decline for emerging market stocks in four years.

In total, last quarter's selloff erased nearly $11 trillion in value from stocks around the world.