As Democrats Lead Early Senate Races, Midterm Elections Could Jolt Stocks if They Sweep Congress

Early results and market forecasts

The first seven Senate contests called on election night went to Democrats. As voting ended, prediction-market data showed growing expectations that the party could win control of both the Senate and the House of Representatives.

Kalshi put the odds of Democrats capturing the House while Republicans held the Senate at 13 percent. It placed the chance of a Republican sweep at 2.7 percent, based on its bettors’ activity.

Polymarket’s Tuesday figures showed a 75 percent chance of Democrats winning the Senate, while Republicans had a 26 percent chance of keeping it. For the House, Polymarket gave Democrats a 95 percent chance and Republicans a 6 percent chance of retaining control.

Billions in election bets

Kalshi reported that more than $1.6 billion in wagers on the midterms had been placed through the platform this year. The figures reflect bettors’ expectations, rather than confirmed election outcomes.

Political stakes and polling

A Democratic takeover of both chambers would be a major blow to Trump as he begins the final two years of his presidency. Polls have pointed to difficult prospects for Republican candidates amid anger over the rising cost of living and Trump’s unpopular war in Iran.

Democratic candidates have gained ground in polling, including in strongly Republican states. In Texas, Democratic Senate hopeful James Talarico is running neck and neck with Republican Attorney General Ken Paxton.

House race remains competitive

Republicans currently control the House with 219 seats, compared with 214 for Democrats. A party needs 218 seats to hold a majority, and several polls have indicated Democrats have a strong chance of reaching that mark.