Wall Street is bracing for stocks to tumble if Democrats regain control of both houses of Congress.
It seems likely that voters will give the party a majority in at least the House of Representatives.
The outlook for the Senate is much less certain, but recent polls have shown Democratic candidates ahead in key races.
Even with the control of a single wing, the party; It will gain a majority in committees that can propose laws and hold hearings, including on issues such as artificial intelligence, which are critical for the future of markets.
Investors are expecting a more relaxed outlook as historical data points to a rise in stocks regardless of the election outcome.
Wells Fargo & Co. An analysis by found that the S&P 500 Index rose in the 12 months following every midterm election in the post-World War II era.
Truist Advisory Services Inc. Data compiled by shows that stock prices tended to fall in the months leading up to the midterm election vote.
The market usually starts to climb again shortly before the election. But in 2026, the S&P 500 has weathered the typical downturn, rising 13 percent since the beginning of the year.
There are additional reasons to predict that stocks will advance no matter what happens in November. First, President Donald Trump will continue to retain veto power over legislation that would be difficult for Congress to override.
This means that even if Democrats control both chambers, they will have a hard time implementing tax increases or regulatory measures that markets do not like.
Additionally, the economy is expected to continue growing in 2027 and consumer spending has remained strong; These are both trends that generally move stocks higher. Still, the 2026 election is unusual; because a single issue, the construction of artificial intelligence data centers, has mobilized voters across the political spectrum.
That raises risks for investors who don't want new restrictions on the AI infrastructure boom that has been the engine of the four-year bull market in U.S. stocks.
Divided Congress scenario
Wall Street pros are generally happy with the gridlock in Washington, and that's largely what they can expect if Democrats take back just one house of Congress.
Taking any action will be difficult with the House and Senate divided and Trump able to veto any bipartisan legislation.
This means companies and investors can focus on profits and the economy rather than policy changes.
Corporate profits have exploded this year and U.S. gross domestic product has grown at a steady pace.
A blocked Congress is an ideal outcome for the stock market against this backdrop, says Stuart Kaiser, head of U.S. equity trading strategist at Citigroup.
Gridlock has historically tended to provide strong returns to investors.
Under a Republican president and a divided Congress, U.S. stocks have risen an average of 13.7 percent annually since 1950, according to data compiled by Carson Investment Research.
This compares with average gains of 8.3 percent and 4.9 percent during periods when Congress was controlled by Republicans and Democrats, respectively. A historically divided Congress also tends to support bond prices, mainly because the gridlock reduces room for additional fiscal stimulus such as tax cuts.
This could be a boon for stocks in sectors like manufacturing by lowering borrowing costs. The surprise card in this scenario is Trump, whose tariffs and foreign interventions have caused major market fluctuations without the involvement of Congress.
Scenario of overwhelming victory of Democrats
Democrats taking over the House and Senate could trigger a selloff in stocks.
That's partly because the party is more likely to support AI regulations, whether it's placing restrictions on data centers or rules on the development of AI models themselves.
Anything that slows the AI boom will restrict the flow of money to the chipmakers and industrial companies that supply the data centers, while making it less likely that the tech companies selling the AI itself will reap the massive profits that stock market investors will eventually demand. It will be difficult to actually pass AI laws.
Trump has positioned himself as a supporter for technology and is likely to veto any bill that is too restrictive. Democrats are almost certain to fall short of the qualified majority they would need to override the veto.
This means that what initially looked like a big win for Democrats could still end in a deadlock. This is Microsoft Corp. and Nvidia Corp. It will likely limit the risk to the profits of AI leaders like.
Still, Democrats will be able to keep up the pressure on AI companies by conducting investigations into the industry and holding public hearings.
Investors could also read a landslide Democratic victory as a sign of the direction politics will take after Trump leaves office.
On a sectoral basis, the healthcare industry could get a boost if Democrats use their influence to roll back cuts to Medicaid, the health insurance program for low-income Americans.
Defense contractors are already on edge due to concerns that the party will scrutinize military spending more closely.
In the bond market, a landslide Blue victory could put pressure on prices if Trump, as a lame-duck president, turns more toward executive orders, including imposing new tariffs or escalating geopolitical tensions.
The Democrats' victory could also put pressure on the US dollar as market participants predict that a slowdown in artificial intelligence will negatively impact the economic outlook. But given other factors working in the dollar's favor, including high energy prices and expectations that the U.S. Federal Reserve will raise interest rates, the election is unlikely to meaningfully move the $9.5 trillion daily foreign exchange market.
Scenario of overwhelming victory of the Republicans
Analysts said the current favorable environment for AI stocks should be maintained if Republicans manage to retain control of both houses of Congress, an outcome that polls show is unlikely.
“Maintaining the status quo wouldn't be a bad thing in itself,” said Matt Miskin, strategist at Manulife John Hancock Investments. A rally could begin in financial and industrial stocks closely tied to the economy as investors bet Republicans will take action to boost growth. However, this growth may put the brakes on both economic expansion and stock market rise by increasing borrowing costs.
Traders are treading cautiously as Congressional control remains uncertain before the US polls open. The election adds an additional layer of risk for investors already struggling with geopolitical headwinds at a time when the once-dominant AI trade is experiencing a sharp pullback. “Investors are going into the midterm elections very cautiously,” said Alexandre Drabowicz, global chief investment officer (CIO) at Indosuez Wealth Management.
Historically the S&P usually continues its climb afterwards and the fundamentals remain very, very strong. "We need to leave this incident behind," he said.
