NEW YORK: US midterm elections rarely produce major market fireworks, but Tuesday’s contests could introduce new uncertainties around artificial intelligence spending, debt ceiling negotiations, and federal regulation.
Since Donald Trump returned to the White House in 2025 with full Republican control of Congress, the S&P 500 has gained about 27% amid strong corporate earnings and AI capital spending.
However, Treasury yields remain elevated following energy price pressures earlier in the year. Current forecasts suggest Democrats could capture the House, while control of the Senate remains closely contested.
Market strategists note that divided government or a Democratic congressional sweep could lead to tougher oversight of the tech sector.
“Probes could speed up efforts to require safety standards for frontier AI models,” said Ed Mills, Washington policy analyst at Raymond James.
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Such investigations could temper the rapid expansion that investors have priced into technology equities. Meanwhile, a split Congress raises the risk of fiscal gridlock, government shutdowns, and debt-limit brinkmanship as the nation approaches 2027 budget deadlines.
Diego Barnuevo, a market analyst at Ebury, said a Democratic-led legislature would likely confine negotiations to must-pass funding bills.
Conversely, a Republican sweep would reduce regulatory pressure on AI infrastructure and maintain policy continuity for corporate tax reform and defense spending.
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Economists warn, however, that such fiscal expansion could widen the national deficit and increase long-term pressure on sovereign ratings.
Historical data compiled by Ned Davis Research shows that when the president’s party loses the House, the S&P 500 has posted a median gain of 1.4% from Election Day through year-end across past midterm cycles.
(With input from Reuters)
