Since 1928, the S&P's performance after presidential elections has provided valuable lessons for investors.

• The stock market's performance during past presidential elections provides no clear indication of how it will react to the upcoming election.
• In the 12 months after presidential elections, the S&P 500's performance has been unpredictable and varied.
• Experts advise investors to adhere to their strategy, according to a simple lesson.

The stock market's performance during past presidential elections provides no clear indication of whether the upcoming election will be good or bad for investors.

In the year following President Joe Biden's election in 2020, the S&P 500 experienced a gain of over 42%, according to data from Morningstar Direct. Morningstar analyzed the returns for the six and 12 months following Election Day for all 24 U.S. presidential elections.

In the 12 months after Jimmy Carter's victory over Gerald Ford, the index fell around 6%. Similarly, it dropped around 6% in the year following Dwight Eisenhower's second win.

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A year after Ronald Reagan's first election, the S&P 500 increased by 0.6%. Twelve months after his reelection, the index grew by approximately 19%.

Jude Boudreaux, a certified financial planner and partner with The Planning Center in New Orleans, stated that when examining the performance of stocks following presidential elections, "there is no evident and distinguishable pattern."

According to Boudreaux, a member of the CNBC FA Council, election years are not significantly different from a typical year in the stock market.

In other words, the market's movements are just as unpredictable.

Boudreaux stated that he does not suggest any significant alterations for his clients in light of President-elect Donald Trump's victory.

Morningstar Investment Management's global chief investment officer, Dan Kemp, gave investors the same advice.

Kemp stated that when investors encounter uncertainty, they may look for narratives that forecast the future and subsequently adjust their portfolios accordingly.

An investor's most crucial action is to adhere to their strategy, as stated.