Markets · Kalshi ·September 13, 2026 ·Edited by Samuel Jo

S&P 500 defies September slump, eyes positive year

The S&P 500 has demonstrated resilience, with analysts observing a departure from the typical September downturn. This year, the index has shown strength that could see it close 2026 in positive territory. The market's current trajectory suggests a potential year-end finish above 6845.50, a prospect that traders are currently putting at 86%.

Background

The S&P 500 index, a key barometer of U.S. stock market performance, has historically experienced a challenging September. This seasonal weakness has often led to speculation about its year-end performance. Over the past period, expectations for the index's annual close have fluctuated, reflecting ongoing market dynamics and economic sentiment. The question of whether it will end the year above 6845.50 remains a significant point of interest for investors.

The precedent

• September has historically been the worst-performing month for the S&P 500, with average losses since 1928.
• The S&P 500 has finished positive in roughly 70% of all calendar years since its inception.

Context compiled by Crowdtells from the public record — verify before relying on it.

What to watch

Investors will closely monitor the S&P 500's performance through the final months of 2026, particularly as it approaches the December 31 resolution date. Any significant economic data releases or corporate earnings reports could serve as catalysts, potentially influencing the index's ability to maintain its upward momentum and close above the 6845.50 threshold.

AI-written briefing grounded in 1 source and the live market, edited by Samuel Jo. Odds are crowd probabilities, not advice — how this works.