Prediction markets are signaling a sharp shift in expectations for the 2026 U.S. midterm elections, with traders on the regulated exchange Kalshi now assigning an 85% probability that Democrats will win control of the U.S. House of Representatives, the highest level recorded on the platform.

What Happened

Data from the Kalshi market titled “Which party will win the U.S. House?” shows contracts pricing a Democratic victory at 85 cents, implying an 85% probability, while the Republican Party is priced at 16 cents, reflecting roughly 15% odds of retaining control.

The chart indicates the probability of a Democratic win has climbed steadily over the past several months after dipping briefly late in 2025.

The market has already recorded more than $6.7 million in trading volume, suggesting sustained activity among traders betting on the outcome of the 2026 congressional elections.

Prediction markets function as real-time probability engines in which traders buy or sell contracts tied to future events.

Prices fluctuate based on supply and demand, and a contract trading at 85 cents effectively reflects an 85% perceived likelihood of that outcome occurring.

Polymarket Shows Mixed Expectations On Overall Midterm Balance

While Kalshi traders appear strongly confident about Democrats taking the House, betting patterns on the decentralized prediction platform Polymarket paint a more nuanced picture of the broader congressional balance of power.

Polymarket’s market titled “Balance of Power: 2026 Midterms” currently shows a 48% probability of a full Democratic sweep, defined as Democrats controlling both chambers of Congress.

The same market assigns 35% odds to a split outcome where Republicans hold the Senate while Democrats control the House, and 17% odds of a Republican sweep of both chambers.

Also Read: USDC Surpasses USDT In Transaction Volume For First Time Since 2019

A fourth scenario, Democrats controlling the Senate while Republicans hold the House, trades at around 1% probability.

The Polymarket market has already recorded more than $3.4 million in trading volume, with nearly $944,000 traded specifically on the “Democrats Sweep” contract.

The two prediction platforms suggest traders see the House as the chamber most likely to flip, even if control of the Senate remains more uncertain.

Midterm Elections Historically Favor The Opposition Party

The prediction market surge aligns with a long-standing historical pattern in U.S. politics.

Midterm elections occur two years into a presidential term and determine control of the House of Representatives and roughly one-third of the Senate.

The next U.S. midterms are scheduled for November 3, 2026.

Historically, the political party controlling the White House tends to lose congressional seats during midterms.

Since World War II, the president’s party has lost an average of roughly 25 seats in the House, according to historical analyses of election outcomes.

Given that Republicans currently hold a narrow majority in the House, roughly 220 seats compared with 212 held by Democrats, a swing of only a handful of districts could change control of the chamber.

Read Next: Prosecutors Urge Court To Reject Sam Bankman-Fried’s New Trial Request