The VIX most often will trade opposite SPX.  But Tuesday it rose along with it.  That’s not too unusual for one day, but the same thing also happened Monday.  This triggered the study below which was last seen in the 5/16/13 subscriber letter.  I discussed the results in some detail in last night’s letter, and have shown the profit curve below assuming a 1-day holding period.

Overall the results appear to suggest a moderate downside edge for Wednesday.