U.S. flags at the Washington Monument, the dome of the U.S. Capitol can be seen in the background.
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Control of the U.S. Senate in this year’s midterms remains a tossup just over six months from election day, according to traders on prediction markets platform Kalshi.
Traders give both Republicans and Democrats a 50% chance of winning control of the upper chamber.
While traders have Democrats as favorites to flip control of the House of Representatives, odds in the Senate have narrowed in 2026.
Republicans saw their odds of maintaining their majority fall from 67% on January 1 throughout that month and February, but the declines intensified in March as traders priced in the political consequences of the U.S.-Iran war. Since the start of the conflict, President Donald Trump‘s approval rating has fallen to its lowest levels of his second term in many polls.
Democrats have an uphill climb to flip control of the Senate, as the party will have to win multiple states that Trump won in 2024 by double-digits — like Ohio, Iowa, Texas or Alaska — to have a shot at a majority. However, in the middle of April, Democrats were priced with a 54% chance to win the chamber.
In a Friday note, Bank of America economist Claudio Irigoyen said these odds are having an impact on policy.
“The interesting thing about these moves is that, coupled with falling approval ratings for the US administration, incentives are mounting for the war in Iran to reach a resolution,” Irigoyen wrote. “In our view, this is evidenced in the US administration’s push to reach a deal.”
Traders on Polymarket also see the Senate as a tossup, with Democrats holding a 52% chance of winning while Republicans hold 50% odds.
Disclosure: CNBC and Kalshi have a commercial relationship that includes a CNBC minority investment.
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