Polymarket and Kalshi, two of the largest prediction-market platforms, now put Democrats’ odds of winning the U.S. House in the 2026 midterms at 86%. Tens of millions of dollars have been wagered across hundreds of individual races and primary markets, signaling a sharp shift in expectations for the next congressional cycle.
House odds tilt blue
As of this week, the implied probability of Democrats flipping the House has climbed to 86% on both Polymarket and Kalshi. That’s a dramatic edge for a party that currently holds the minority. The markets aggregate bets from thousands of traders, and the volume — tens of millions of dollars — suggests the crowd sees a strong Democratic wave building.
Republicans, who now control the House by a razor-thin margin, face a challenging map. Several GOP incumbents in swing districts are already retiring, and the party’s narrow majority leaves little room for error. Prediction-market participants appear to be pricing in those vulnerabilities.
Senate stays red
The Senate picture is different. Republicans are given the edge to hold the chamber in 2026, according to the same markets. Democrats would need to defend several seats in red states, including West Virginia, Montana, and Ohio, while the GOP has fewer seats up for grabs. The asymmetry in the map makes a Republican hold the more likely outcome in the eyes of bettors.
That split — Democrats likely winning the House but Republicans likely keeping the Senate — would create a divided Congress if it holds. That scenario has happened before, but the market’s current confidence in a split is unusually high.
Big money on the line
The sheer volume of money flowing into these markets is notable. Tens of millions of dollars have been placed on 2026 midterm contracts, covering everything from control of each chamber to individual primary outcomes. Polymarket and Kalshi have emerged as the dominant platforms for political betting, drawing both casual traders and sophisticated investors.
Regulators have taken notice. The Commodity Futures Trading Commission has been scrutinizing prediction markets, and Kalshi recently won a court ruling allowing it to offer election contracts. Polymarket operates from outside the U.S., but its contracts are still accessible to American users through workarounds. The legal landscape remains unsettled.
For now, the markets are speaking loudly. Democrats are heavy favorites for the House; Republicans are slight favorites for the Senate. But with the 2026 elections still more than a year away, those odds will shift as candidates emerge, campaigns unfold, and the political winds change. The only certainty is that the betting will continue.
