The US dollar has fallen sharply after the Democrats won control of the Senate and the House in the midterm elections, sparking fears that greater regulation of AI could slow economic growth.

The dollar hit a one-month low on Wednesday while coming under pressure from falling bond yields, as investors moved into US treasuries, viewed as a safe haven from the political gridlock anticipated during the rest of Donald Trump’s final term in office.

The dollar index, which measures it against a basket of six currencies, slid to its lowest level in a month and the pound and the euro gained against the dollar. The US currency also slid against the yen and the Swiss franc, currencies that traders tend to turn to during times of uncertainty.

Meanwhile, the 10-year Treasury yield fell by almost five basis points to 4.915%.

American voters rejected Trump and the Republican party’s agenda across the country, as the Democrats’ “blue wave” led to the party securing Senate seats in traditional Republican strongholds such as Texas, Iowa, North Carolina and South Carolina.

Axel Rudolph, the chief technical analyst at the trading platform IG, said: “The scale of the losses will inevitably raise questions about Trump’s ability to push through his agenda over the next two years, and markets are already reacting. The dollar is under pressure as investors reassess the political outlook, while gold and silver are benefiting as safe haven plays.”

Futures trading initially indicated US stock markets would open sharply lower, with the tech-heavy Nasdaq expected to slide on fears over the prospects for AI companies. However, indicators later suggested Wall Street could open higher as Trump’s conciliatory tone and rises on European markets cheered investors.

“Some individual names are nursing significant losses today,” said Kathleen Brooks, the research director UK at XTB. “SpaceX is down 5% in the premarket, and Tesla is lower by more than 4%. Elon Musk is considered an anathema to most Democrats.”

Musk, the world’s richest person, pumped $446m (£331m) into the midterms, funding Republican-aligned political action committees and groups.

Brooks said investors were reacting to expectations that a Democrat-controlled Congress could mean greater scrutiny for AI companies, which could also cast doubt on a potential merger between Musk’s two companies.

The price of gold, a traditional safe haven asset, rose by 2.2%, soaring past $4,000 an ounce.

AI-related shares tumbled during Asian trading hours, on expectations that Democrats will want to bring in greater regulation of the sector.

“I think the fear is that the pace of the AI infrastructure rollout could slow, potentially quite markedly in Texas, as they start to digest exactly what mandate they might have in terms of AI,” said Tapas Strickland, the chief market strategist at Moomoo ANZ.

Jesper Koll, an expert director at Monex Group, said: “The AI momentum has turned negative, with or without the Republicans having a majority. The starting point for financial markets into this election, particularly for the equity market, has been adverse on AI.”

Trump’s style of governing through executive orders has prompted some analysts to question whether the Democrats regaining control of Congress will have much change on US policymaking.

“There’s still a number of areas where Donald Trump can influence the markets – trade and tariffs, foreign policy, and existing regulations,” said Tai Hui, a market strategist at JP Morgan Asset Management.