The Zhitong Finance App notes that historical analysis shows that the US stock market often continued to rise in the 12 months after the midterm elections. However, rising US bond yields, inflation risks, and uncertainty surrounding AI spending may test this pattern in 2027.
This historical record gives investors reason to look at the period after the November 3, 2026 midterm elections.
However, that doesn't guarantee another year of growth. Historical performance unfolded in a very different economic environment, and some of the strongest post-election periods also experienced sharp pullbacks during these periods.
The question facing investors is whether this historical pattern can be replicated in the next 12 months, or whether current concerns about inflation, high US bond yields, fiscal uncertainty, and questions about AI-related capital expenditure will make the current cycle different.
The S&P 500 Index recorded an increase in 12 months after all 19 midterm elections
Historical data shows that in the three time periods examined (3 months, 6 months, and 12 months after the midterm elections), the average return was positive. The strongest average performance occurred over a 12-month period.
The average return for 12 months was 15.1%, 6 months was 12.8%, and 3 months was 6.3%. This pattern shows that over a longer period of measurement, the upward trend is more stable than the trend that appeared immediately after election day.
The results were not all strong. The 12-month return ranged from 1.1% to 33.2%, with a difference of over 32 percentage points. Short-term performance was also less stable: the index declined in the first three months after the 2002 and 2018 midterm elections, then rebounded, both ending with 12 months of positive returns.
Therefore, the data points to a historical trend rather than a steady, uninterrupted post-election upward trend.
The historical record is encouraging, but there is a great degree of dispersion between cycles. The 12-month return ranged from 1.1% to 33.2%, with a difference of over 32 percentage points.
The chart shows that the 12-month positive return results are more stable than the short-term results. Although two cycles started off below the first three months, they all recorded positive returns for 6 and 12 months thereafter.
The historical record is encouraging, but average values alone don't tell the whole story.
Why do stocks tend to perform better after the midterm elections?
There are several possible explanations for this historical pattern, although none can prove that the midterm elections themselves were the reason for the rise in the stock market.
Eliminating political uncertainty
The election campaign created uncertainty surrounding congressional control, fiscal policy, taxation, trade, regulation, and government spending.
Once the election results are more clear, investors can re-evaluate the likely policy environment and adjust expectations. This could reduce a source of uncertainty and allow the market to refocus on corporate profits, economic growth, and monetary policy.
However, the elimination of political uncertainty does not necessarily eliminate market risk. A contentious outcome, policy differences, or a protracted legislative impasse could carry the uncertainty beyond election day.
Third year of the presidential cycle
The midterm elections take place in the second year of the presidential term. The next calendar year is traditionally known as the third year of the four-year presidential market cycle.
Historical analysis shows that this is often the year with the strongest performance for US stocks during the presidential cycle.
According to historical analysis quoted by Pepperstone, the average return of the S&P 500 index in the third calendar year of the presidential term from 1951 to 2023 was 17.2%.
One explanation is that before the next presidential election, the government may prioritize economic growth and policies aimed at supporting business activity. However, this is still a historical observation and not a reliable predictive model.
There may be a split government
Investors generally believe that splitting the government may be a more favorable environment for the stock market because it can limit drastic legislative changes and reduce the possibility of a sudden shift in policy.
However, there is little evidence of historical returns that a split government alone can explain the post-election rise.
Of the 19 midterm elections since 1950, 14 have resulted in split governments. During these periods, the S&P 500 increased by an average of 15.1% over the next 12 months.
After five elections leading to a unified government, the average return was almost the same, at 15.0%.
This suggests that the political landscape itself may not be as important as the economic and financial situation at the time.
12-month positive returns don't mean a steady market recovery
One of the biggest limitations of relying on the historical average is that it only measures performance at two points in time, not the fluctuations experienced over time.
In 11 of the 19 post-midterm elections, the S&P 500 experienced the biggest pullback of more than 10% in the following 12 months.
The 1986 cycle is a particularly prominent example. The index rose 17.5% in the six months following the election, but the October 1987 stock crash then erased most of that increase. The benchmark index fell 33.2% from its peak in August to the bottom of October, and ended up only 1.1% at the end of the 12-month period.
The 2010 cycle provides another example. Although the S&P 500 index rose 14% in the first six months after the election, it later fell into trouble due to an impasse in the US debt ceiling, downgraded national credit ratings, and Europe's sovereign debt crisis. The index experienced a 19.4% retracement and eventually rose 3.7% at the end of the 12-month period.
In 2018, the Federal Reserve raised interest rates and trade tension between China and the US escalated, causing the index to fall 16.4% between November and December. 12 months after the midterm elections, the index is still up 11.7%.
The 2022 cycle also explains why investors should differentiate between election-related developments and macro-catalysts. The S&P 500 index fell 2.1% the day after the election and rose 5.5% the next day, as lower-than-expected inflation data raised less aggressive expectations for the Federal Reserve.
The 12-month increase that followed was 14.5%, although the index experienced a 10.3% retracement during this period.
These examples show that historical post-election rules are no substitute for monitoring valuations, monetary policy, and economic risk.
How are the 2026 midterm elections different?
As the November 3, 2026 election approaches, investors are weighing several competing forces.
Since Trump returned to the White House with the Republican-controlled Congress in 2025, the S&P 500 has risen about 27%, supported by strong corporate profits and massive investment in artificial intelligence infrastructure.
However, US bond yields have also risen sharply, and energy-driven inflation concerns and the US fiscal outlook have become important considerations for investors.
This election could change the legislative environment for the last two years of Trump's term. All 435 seats in the House of Representatives and 35 seats in the Senate will be re-elected, making the election results closely linked to the direction of fiscal policy, regulation, trade, and government spending.
Sectors may be affected differently
AI and technology: If the Democratic Party takes control of one or both chambers of parliament, it may increase congressional scrutiny of large technology companies, AI security standards, and data center construction. This could create additional regulatory uncertainty for companies investing heavily in AI infrastructure.
Conversely, if the Republican Party continues to control Congress, it may support policy continuation, deregulation, and approval initiatives, thereby favoring the AI infrastructure investment cycle.
Defense and industry: A major Republican victory could create more room to increase defense spending and adjust tax policies. Although this may benefit some defense and industrial companies, additional deficit financing expenses may also put pressure on US bond yields.
Finance and the broader US business: Changes in regulation, tax policies, and fiscal priorities may affect banks, insurance companies, and other capital-intensive businesses. However, the impact depends on the specific legislation being promoted, not just on congressional control.
US debt and the dollar: The fiscal impact of the election may be particularly important for bond investors. If the election results raise concerns about government borrowing and debt sustainability, higher US bond yields could drive up borrowing costs and put pressure on stock valuations.
Investors are also concerned about possible debt-ceiling disputes and government funding negotiations in 2027. Thus, elections are important not only because of which political party gains control by Congress, but also because of how the election results affect expectations of government spending, corporate investment, and capital costs.
What investors should look out for after Election Day
Historical records provide a constructive starting point, but the next phase of the market will depend on whether corporate profits and economic conditions can support stock valuations.
Three variables are particularly noteworthy.
Federal Reserve Policy and US Treasury Yield
Interest rates are still one of the most important determinants of stock valuations. Higher US bond yields have increased the discount rate applied to future corporate profits, which may put pressure on growth stocks and companies whose valuations are highly dependent on future cash flow.
Continued increases in yields are likely to offset the positive effects of reduced political uncertainty.
Corporate Profitability and AI Capital Expenses
The strength of corporate profits is critical to maintaining market gains. Investors need to assess whether AI-related investments are translating into measurable revenue growth, productivity gains, and operating profitability.
Companies that continue to increase capital expenditure without showing a commensurate return may face more stringent scrutiny, particularly as financing costs remain high.
Inflation and economic growth
The interaction between inflation and economic growth will shape the Federal Reserve's policy choices.
The economy remains resilient and inflation tends to moderate, which will provide a favorable background for earnings and stock valuations. Conversely, continuing inflation may constrain monetary easing, while worsening employment and consumer demand may heighten fears of a recession.
The impact of these factors on market performance is likely to be more direct and lasting than the election results themselves.
summed
Historical evidence is hard to ignore. Since 1950, the S&P 500 index has recorded an increase in the 12 months after all 19 midterm elections, with an average price return of 15.1%.
However, this pattern should be viewed as a historical trend rather than a prediction. Nearly the same returns from a split government and a unified government suggest that congressional control itself is not a reliable determinant of post-election market performance.
As far as 2027 is concerned, investors need to look beyond political headlines. The trend in US bond yields, inflation, Federal Reserve policy, corporate profits, and returns from AI-related investments will more importantly determine whether the market can continue its historic post-midterm gains.
Elections may remove a layer of uncertainty, but they cannot eliminate the economic and valuation risks that ultimately determine stock prices.