A sweeping victory by Democrats in the US midterm elections sent the dollar tumbling on Wednesday, as investors weighed the prospect of tighter AI regulation and its potential drag on economic growth.

Several major currencies gained versus the dollar, with the euro and sterling trading at their highest levels in nearly two weeks and seven weeks, respectively.

Democrats captured majorities in both the Senate and the House, even prevailing in states that have long been conservative bastions, stoking fears that opposition to data centres may gather fresh momentum.

That also raised concerns about the potential hit to the US economy, given how much US growth has been tied to AI-related spending.