What Prediction Markets Are Forecasting

Prediction markets currently give Daniel Biss, a former Illinois state senator, roughly a 2 in 3 chance of becoming the Democratic nominee for Illinois' 9th Congressional District in 2026. This means traders collectively see him as the clear favorite, but not a guaranteed winner. The contest is for the party's candidate to run in the general election for this reliably Democratic Chicago-area seat, which covers parts of the North Side and northern suburbs. The current representative, Jan Schakowsky, has held the seat since 1999 but is not seeking re-election, creating this open race.

Why the Market Sees It This Way

Traders are betting on Biss for a few specific reasons. First, he has significant local political experience and name recognition. He served as a state representative and senator for the area, and was the Democratic nominee for Illinois Comptroller in 2010. He also ran a competitive statewide primary for governor in 2018, finishing second. This established political base is a major advantage in a local party nomination process.

Second, Biss has already declared his candidacy and is actively campaigning. This early start allows him to lock in support from local Democratic organizations and donors before potential rivals fully organize. In a district where the Democratic primary winner is almost certain to win the general election, securing the party's nomination is the real contest.

Finally, while other candidates may emerge, no opponent with comparable stature and resources has yet entered the race. The market reflects a belief that Biss's head start and political network will be difficult for another candidate to overcome.

Key Dates and Events to Watch

The primary election is scheduled for March 17, 2026. However, the decisive events will happen much sooner. The most important period is the candidate filing deadline, which is likely in late November 2025. If a well-known challenger files paperwork by then, the prediction could shift significantly.

Before that, watch for endorsements from key local groups like the Cook County Democratic Party or major unions. An endorsement for Biss from a group like this would likely solidify his position as the frontrunner. Conversely, a notable endorsement for a different candidate would be a strong signal that the race is competitive. Fundraising reports, which are public, will also provide clues about the strength of each campaign.

How Reliable Are These Predictions?

Prediction markets have a solid track record in forecasting primary election outcomes, especially when one candidate has a clear advantage in experience and organization, as Biss appears to have here. They often perform better than early polls because they force people to back their beliefs with money.

The main limitation is time. This market is forecasting an event over two years away, which is a very long horizon in politics. Unexpected candidates could enter, local political dynamics might change, or a national issue could reshape the race. The current odds are a snapshot of today's information, not a final verdict. As the filing deadline and primary day get closer, the market predictions typically become more accurate.