SPY closed down a little rather than up a little because it went ex-div. Rather than looking at 10-day highs I looked at closes in the top 10% of the 10-day range. A slightly different twist. (Note that the SPY missed qualifying for this by a few pennies as well thanks to the dividend. Still, I felt the current situation represented the spirit of the setup.)
Rather than a stats table, I've listed below all 11 instances since 2003.
10 of 11 instances saw declines from open to close. The far right column is even more interesting. In only 1 case did the max intraday runup from the opening price exceed 1% (3/16/09). In contrast, 9 of 11 exceeded a 1% pullback, and all 11 exceeded a 0.8% pullback. This all suggests to me that intraday risk/reward is skewed to the downside today.