The S&P 500 rally since the April low is close to the five-month mark. it’s up about 34% through the most recent high on August 28. Whether that proves to be a short-term peak or extends further, the setup suggests we may soon see a more meaningful pullback. So it’s not a question of “if,” but “when.” More importantly, it will be critical to watch how the market responds to the first real body blow.