A Kalsi billboard displays odds for the U.S. Senate midterm elections, Friday, October 16, 2026, in New York, USA.
Michael Nagle | Bloomberg | Getty Images
Democratic support for Mr. Calci is growing, with traders giving Monday a 74% chance that Democrats will win the Senate majority. This is the highest probability since the party launched a market on the platform.
Odds are looking even higher after The New York Times reported Sunday that a poll conducted with Siena College found Democrats leading in several battleground states, strengthening their path to a Senate majority.
The contract asks, “Who will control the Senate?” It will be verified by the Library of Congress after Tuesday’s vote.
Since the Republican Party took office in 2024, the market for a Senate majority in 2026 has been dominated by Republicans. Immediately after the United States and Israel launched their first attacks on Iran on February 28, the difference in odds between the two parties narrowed, but the probability of a Republican majority jumped to 60% in July, before reversing in mid-September.
In the past 24 hours, there has also been a significant movement in favor of Democratic candidates in the market for individual Senate races. Carsi traders now see the odds of a Democrat winning the Texas Senate race going from 68.4% to 74% in the past 24 hours. The market for the Iowa Senate race increased from 42% of polymarkets to 50%, favoring the Democratic Party.
In Kansas, which has not elected a Democratic senator since 1932, Democratic candidate Adam Hamilton’s odds of defeating Republican Roger Marshall have increased from 52% to 63%.
Odds and gambling platforms are not replacements for political polls, as they do not use the techniques used in traditional political polls.
Disclosure: CNBC and Kalsi have a commercial relationship that includes customer acquisition and minority ownership.
