S&P 500 September Curse May Fail? Strategist Sees 2026 Strength

Despite September's long-standing reputation as the S&P 500's worst month of the year, Carson Group chief market strategist Ryan Detrick argues that the market's year-to-date strength suggests 2026 could break this historical pattern.

Historical Odds Favor the Bulls

Seasonal anxiety typically peaks at the start of September, but Detrick emphasizes that when stocks enter September on solid footing, history tells a much more optimistic story. In a post on X, Detrick acknowledged September's seasonal reputation while highlighting key historical exceptions during strong market years.

"Yes, September is historically the worst month of the year. Get ready to hear a lot about that next week," Detrick posted. "But when August finishes higher and the year-to-date start is solid, things actually look pretty good."

Looking back at data since World War II, when the S&P 500 posted a positive August and year-to-date gains between 10% and 17.5%—a scenario matching 2026's current 3% August gain and 12.8% year-to-date return—September itself averaged a 1.0% gain.

More importantly, in 11 similar instances, the final four months of the year finished higher 10 times, with average returns of 5.6%.

Yes, September is historically the worst month of the year. Get ready to hear a lot about that next week. But when August finishes higher and the year-to-date start is solid, things actually look pretty good.

In fact, the rest of the year saw only one decline, and...

— Ryan Detrick, CMT, August 27, 2026

Key Technical Levels and Seasonality

During an episode of the Facts & Feelings podcast, Detrick noted that seasonal turbulence remains possible, particularly given broader political and election-year dynamics. "In midterm election years, August and September have historically been troublesome and volatile," Detrick acknowledged.

However, Detrick maintains that strong internal market breadth and technical support levels bode well for investors. He specifically highlighted the 7,610 level—the S&P 500's June 2 high—as a crucial floor.

"Previous peaks or prior resistance levels should become new support," Detrick noted, adding that as long as the index holds above 7,610, the broader technical picture remains constructive.

Given historical records and internal market factors aligning with the bulls, Detrick urges investors not to panic over calendar-based fears.

How Is the 2026 Market Performing?

The S&P 500 is up 12.72% year-to-date. Similarly, the Nasdaq Composite has gained 14.23%, while the Dow Jones Industrial Average is up 10.72% year-to-date.

On Thursday, the SPDR S&P 500 ETF Trust, which tracks the S&P 500, and the Invesco QQQ Trust ETF, which tracks the Nasdaq 100, both closed higher. SPY rose 0.66% to $771.10, while QQQ gained 1.37% to $721.11. Meanwhile, the SPDR Dow Jones Industrial Average ETF Trust, which tracks the Dow, closed up 0.19% at $535.22.

In Friday's premarket trading, SPY was up 0.02%, QQQ was down 0.17%, and DIA was up 0.05%.