Sen. Roger Marshall leads Adam Hamilton comfortably in the betting markets even though a recent survey puts the Democrat ahead.
Prediction markets and pollsters are telling two different stories about the Senate race in Kansas.
On Kalshi, Republican Roger Marshall trades at 70% to win, with Democrat Adam Hamilton at 30%, on total volume of $1,990,113. Polymarket puts Marshall at 71% on about $327,000 in volume. Yet a Emerson College poll showed Hamilton leading 45% to 43%.
Why the markets discount the poll
The gap is wide. A two-point polling lead can fall within a survey’s margin of error. The poll’s own methodology and uncertainty are needed to assess the significance of that gap. The markets, by contrast, price Marshall as better than a two-to-one favorite.
The likeliest explanation is history. Kansas has not elected a Democrat to the Senate since 1932. Traders appear to be weighting that 94-year record more heavily than a single survey.
Where the money is
Kalshi's market in the race has attracted about six times the volume of Polymarket's, and the two platforms agree within one percentage point. The similar prices show agreement across platforms at that moment. Trading volume alone does not establish liquidity, independence of participants or forecasting accuracy.
What would change the price
The price has barely moved in recent sessions. The next new poll is the most likely catalyst. A second survey showing Hamilton ahead would test whether traders are discounting the data or simply waiting for confirmation. A poll showing Marshall back in front would likely push his odds higher still.
What to watch
New public polling, campaign fundraising disclosures and national shifts in the midterm environment ahead of the election, now 34 days away.