Opex week during October has typically been a strong week for the market.  This can be seen in our op-ex week breakdown by month from March.  And much of the upside edge has been thanks to the strong op-ex Monday returns.  But op-ex Monday in 2008 was SO unusually strong (11.5% 1-day gain) that I decided to run the numbers excluding it.  So here is a look at October op-ex Mondays since 1984 not including 2008.

As you can see the numbers are still very favorable.  There appears to be a bit of a bullish seasonal edge today.