Historical Data Shows S&P 500 Typically Rises After Midterms Despite Current Volatility

Key points

• The S&P 500 has posted positive one-year returns in 91% of cases following both presidential and midterm elections since 1980, averaging a 13.7% gain after midterms.
• Markets historically perform better when power is divided between the White House and Congress, with one-year returns averaging 15% compared to 11.5% under single-party control.
• Short-term market reactions are less reliable, with the index averaging a 0.2% rise after one day and one week, but often showing slight declines immediately after presidential contests.
• A scenario where Democrats control Congress while a Republican holds the presidency has historically resulted in a 10.9% gain one year later, despite initial negative reaction days.
• Current risks include AI sector volatility, rising global bond yields, geopolitical tensions with Iran, and Federal Reserve policy, which may override historical seasonal patterns.

Background

Recent coverage has highlighted that 2027 is expected to be the strongest market year of President Trump's second term based on historical post-midterm performance. Previous reports noted a sharp divergence between AI-heavy tech stocks and the broader market, with major chip names shedding $5 trillion in value since early October while the rest of the S&P 500 gained $1.3 trillion. Analysts have debated whether unified or divided government benefits investors, with some data favoring unified control while others cite divided government as preferable for regulatory stability. The current midterm window coincides with major corporate earnings and Federal Reserve decisions, adding complexity to historical seasonal trends.

Why it matters

Understanding historical post-election market behavior helps investors navigate political uncertainty and make informed decisions about long-term investment strategies. The consistent pattern of positive returns after midterms suggests that political outcomes are less impactful on markets than other factors like Federal Reserve policy and corporate earnings cycles. However, current conditions involving AI volatility, geopolitical risks, and bond market stress may disrupt historical patterns, making it crucial for investors to monitor these factors alongside political outcomes.

What to watch

Investors should monitor the outcome of the November 3, 2026 midterm elections and assess whether divided or unified government emerges, as this will influence market expectations for spending and regulatory stability. The performance of AI and tech stocks will be critical in determining whether the broader market can sustain its recent gains or faces further retrenchment. Geopolitical developments, particularly regarding Iran and global bond yields, will also play a significant role in shaping market sentiment in the coming months.