September's seasonal weakness is more prevalent in the back half of the month.

We're two-thirds of the way through the third quarter, and corporate earnings — along with macro uncertainty — have revealed some clear winners and losers.

Even after a positive August, historical performance suggests the coming weeks could be challenging.

August was very good for Wall Street. September is shaping up to be the opposite.

September's seasonal weakness is more prevalent in the back half of the month.