How Often is the Dow Negative in May?

I may be getting a little ahead of myself here, but since the Santa Claus rally has been in full effect in 2012, I'm starting to think about the next time that the markets will hit a seasonal turning point.  The next big seasonal mile marker is when we are supposed to "sell in May and go away" 5 months from now.

In the recent past following the adage has been pretty effective.  The Dow has been down 3 years in a row in May, and 4 of the last 5.  In fact, even in 2009 when the market was rallying from the depths of the bear market, the index did take a breather around May.

The fact that seasonality has held so well in May got me to thinking about how and when the streak could end.  After all, in the 113 year history of the Dow, May is only negative a little over 50% of the time.  So will 2013 be a year to shirk seasonality?

Below is a chart that can perhaps help provide some guidance.  It shows the length of Dow losing streaks in May.  There have been three times that the Dow was negative in May for more than 3 years in a row.  The longest streak was between 1965 and 1971 when it was negative 7 years in a row.