Senate odds slip for Democrats; Michigan is the week's biggest mover

Democrats’ Senate probability eases

Democrats remain favored to win the Senate on DeFi Rate’s 3:10 PM ET board, but their probability has fallen to 62%, a decline of 3 points this week, according to DeFi Rate. The update was published on Oct 12, 2026 at 3:54 PM ET.

The Senate contracts were priced at 61.8¢ on Kalshi and 64¢ on Polymarket. Both venues therefore placed Democrats above an even chance, with Polymarket showing the higher price at the cited snapshot.

The House reading remained at 90%, according to DeFi Rate. The available summary also indicates a decline of 2 points, but cuts off before identifying the comparison period.

Michigan was identified as the week’s biggest mover in DeFi Rate’s headline. Neither the size nor the direction of that move appears in the supplied material. With the source page unavailable, there is no further detail on Michigan’s movement or the factors behind the broader Senate decline.

What it means for prediction markets

• Senate favoritism has weakened, not reversed. The 3-point weekly decline leaves Democrats at 62% on DeFi Rate’s board.
• Venue differences matter. Kalshi’s 61.8¢ and Polymarket’s 64¢ are separate market readings, rather than a single uniform price.
• Michigan’s move lacks essential context. Its designation as the biggest weekly mover does not establish which party gained or by how much.