Kalshi and Polymarket both price Democrats as clear favorites, with Kalshi carrying far heavier trading.
Prediction markets continue to see Democrats as solid favorites to win control of the U.S. Senate in the November 3 midterm elections, with odds on both major platforms unchanged over the past day.
Kalshi's Senate control contract prices a Democratic majority at 64%, with Republicans at 36%. Polymarket shows almost the same split, with Democrats at 65%. The one point difference between the two platforms is within the normal spread for contracts on separate exchanges.
Where the money is
Kalshi dominates the activity. Its Senate contract traded about $35.7 million in a single day, compared with roughly $5.1 million in total volume on Polymarket's version. That gap reflects Kalshi's position as the federally regulated venue for U.S. traders and suggests its price is the one institutional and larger retail participants are setting.
Reading stable odds
A market that holds at the same level for consecutive days is not necessarily a quiet market. On Kalshi, tens of millions of dollars changed hands without moving the price, which indicates buyers and sellers are finding equilibrium at roughly two-to-one. That kind of stability usually persists until new information arrives, such as a major poll shift, a candidate controversy or a change in the economic backdrop.
The macro angle
The economy may be that catalyst. With the 10-year Treasury yield near its highest level since 2007 and markets pricing a likely Federal Reserve rate hike in October, borrowing costs are becoming a campaign issue. Higher mortgage rates and tighter credit tend to weigh on the party in power, and traders will be watching whether rising rates translate into movement in the Senate odds.
What to watch
With about five weeks until Election Day, the key signal is divergence. If Kalshi and Polymarket start to separate by more than a few points, it would suggest one set of traders is reacting to information the other is not. For now, both markets agree: Democrats are favored, and the price is steady.