Investors on Wall Street have a playbook for trading the markets around Election Day.

Markets hate uncertainty, the adage goes, and the stock market typically dips in the month before the vote — in October, the S&P 500 index fell about 1 percent — before rallying once the result of the vote is known.

That’s why many on Wall Street expect stocks to gain on Wednesday, provided that there is a clear winner. But given the closeness of the race, and the possibility of an uncertain or contested result, there is still the possibility of turmoil. (That is one explanation for the recent jump in the price of gold, which is considered a haven in times of trouble.)

Even so, a potential spike in short-term volatility for stocks would eventually be eclipsed by long-term gains linked to underlying economic trends, said Seema Shah, chief global strategist at Principal Asset Management. The S&P 500 gained about 57 percent under President Donald J. Trump, measured from Election Day to Election Day, and about 70 percent under President Biden.

In the end, “the market absorbs these events,” said Quincy Krosby, chief global strategist at LPL Financial. “There’s always an understanding that this, too, shall pass, because it always has.”

But beyond this broad bet on the market’s momentum, investors often say it is tricky to make stock bets tied to presidential policy, because it is hard to predict what will pass through Congress and how policies will ultimately affect companies and markets. In addition, the recent wobble in stocks appeared linked to the earnings at the big technology companies that dominate market indexes, highlighting the influence of factors beyond the election.