Since 1998 no month has been stronger than October:

It’s a midterm year.  How have stocks performed historically in the 4th quarter?

October is number 1, November #2, December #3:

And, it’s likely to be a volatile month.  During the last quarter the S&P 500 Index did have a single 1% intra day move.  The last, and only time, this has happened before was back in 1963.  Historically no month has more 1% changes than October:

Something’s gotta give. 

Hat tip Ryan Detrick