US stock futures fell late on Tuesday as investors awaited results from the midterm elections that could reshape the balance of power in Washington.

S&P 500 futures were around 1% lower at 9:30 p.m. ET, while Nasdaq futures fell 1.8%.

Early results showed Democrats making gains in the Senate, although control of both chambers of Congress remained uncertain as votes were still being counted and polls were still open in western states.

The outcome could have implications for President Donald Trump’s economic agenda, including government spending, regulation, and the AI industry, where data center expansion and the political influence of tech billionaires have become flashpoints.

For investors, the scale of any Democratic gains could matter as much as which party ultimately controls Congress.

“A narrow blue wave may be largely priced in. A commanding one could force markets to rethink Trump’s remaining policy agenda and the political trajectory into 2028,” Chris Weston, head of research at Pepperstone, wrote in a note on Wednesday.

A stronger-than-expected Democratic victory, or Republicans defying the odds and retaining control of the Senate, could trigger significant market repositioning, he wrote.

“The greatest market reaction may come not from who wins Congress, but from how decisively they win and how far the result deviates from expectations,” he added.

The cautious mood followed a mixed session on Wall Street. The S&P 500 rose 0.4% on Tuesday and the Nasdaq Composite gained 0.8%, while the Dow Jones Industrial Average slipped 0.4%.