Stocks Tend to Sink During the Summer Before Midterm Elections. Will Hist...

Why It Matters

Seasonal weakness combined with election‑year uncertainty can trigger volatility, influencing portfolio positioning and risk management. Understanding these patterns helps investors anticipate market shifts before they materialize.

Key Takeaways

• S&P 500 historically loses 2.8% from April to September in midterm years
• VIX at 16.7 suggests hidden volatility despite market uptrend
• Divided Congress historically supports equities by limiting major policy shifts
• May and September historically weaker months, adding seasonal risk
• Strong AI earnings buoy market, but macro risks remain

Pulse Analysis

Historical data from Dow Jones Market Data underscores a recurring seasonal dip for equities during midterm election years. From 1928 through 2025, the S&P 500 averaged a 2.8% loss between the end of April and the end of September, with outlier crashes in 1930, 1974 and 2002 inflating the average. Even when those extreme years are excluded, the index barely breaks even, gaining just 0.006% over the same period. This pattern reflects a broader market psychology where investors shift focus from corporate fundamentals to political uncertainty, often resulting in muted or negative returns.

Despite the historical backdrop, the market entered the summer on a strong note, with the S&P 500 up 3.7% in May and all major indexes posting weekly gains. Yet the Cboe Volatility Index (VIX) lingered at 16.7, a level more typical of a cautious market. Analysts such as Nomura’s Charlie McElligott argue that this divergence signals hidden risk, especially as earnings season fuels sector‑specific optimism while macro‑level concerns—higher oil prices, the Iran conflict, and persistent inflation—loom. The juxtaposition of robust AI‑driven earnings against these broader headwinds creates a choppy terrain that could test the market’s resilience.

Politically, the upcoming midterms add another layer of complexity. With Republicans holding a slim majority in the Senate and a narrow edge in the House, a divided Congress is plausible, a scenario historically favorable for stocks because it curtails sweeping fiscal or regulatory reforms. However, the precise composition of Congress will influence policy direction on taxes, spending and regulation, factors that could either reinforce the current equity rally or introduce fresh volatility. Investors should therefore monitor both the seasonal calendar and the evolving political landscape to gauge risk and opportunity.