Is October Bad Luck?

What is the deal with October? Does the stock market have something against the month of October? The Great Crash of 1929 - October 29, 1929; Black Monday - October 19, 1987; Mini crash - October 13, 1997; Crash due to Asian markets - October 27, 1997; and the current economic crisis - October 2008.

Is it due to elections, market timing, beginning of the 4th quarter, or is it all coincidence? Some brief research shows that of the top 20 largest daily percentage loss days of the stock market, 9 of them are dates in October. That is 45%. The top 3 largest daily percentage loss days are all dates in October.

However, the flip side is that of the top 20 largest daily percentage gain days, 6 are in October. If you look at the gain days more closely, you will discover many of these occur a few days after a crash, when investors believe the market has bottomed out, and are speculating that bargains are available.

All that being said, October and the autumn months seem to be when most of the losses on Wall Street occur. Why that is remains a puzzle to me.