S&P 500 averages 13.7% gain in the year after midterm elections; rose in all 11 instances

After the U.S. midterm elections, the S&P 500 has risen over the following year in all 11 instances from 1982 to 2022, averaging a 13.7% gain across elections held from 1980 to 2024, according to a CNBC analysis published Wednesday. The study found that 91% of all post-election one-year returns—covering both presidential and midterm elections—were positive. Short-term performance was less consistent: average returns across both election types were slightly negative one day and one week after presidential elections, with combined averages of 0.2% one day and one week out and 1.1% one month later. The report cautions that the perfect 11-for-11 midterm record does not guarantee gains immediately after voting, as post-election and one-year returns must be assessed over separate observation windows. The analysis comes as markets weigh historical seasonality against current political uncertainty, with investors watching whether the post-midterm pattern holds amid macroeconomic and policy variables that historically shaped the White House-Congress split outcomes referenced in the data.