Kalshi election trading hit $1.1bn in 10 days to 3 November, 3% of volume

Election trading on Kalshi totalled more than $1.1bn in the 10 days ending 3 November, around 3% of platform volume, with sports and parlays driving most activity. The figures come from a Legal Sports Report analysis that drew on TickerTracker prediction-market data.

What happened

Legal Sports Report found that Kalshi handled $25.3bn in parlays over the 10 days, which works out at almost $23 for each dollar traded on elections. A further $6.1bn went through non-parlay sports contracts. Parlays, known as combos on prediction markets, combine multiple outcomes for larger payouts.

On Election Day, election trading made up 17.5% of daily volume and, for the first time, exceeded non-parlay sports. Parlays still drew more than three times as much as elections that day.

Kalshi extended parlays to cover elections ahead of the midterms. Sports have historically led combo trading: a GuardianBlock analysis put their share at 99.3% from 1 to 19 September.

The five largest election markets made up roughly 54% of the $1.1bn. Congressional control contests featured among them, alongside a Senate race and a governor's race in one US state; the largest single contest drew $145m.

Activity dropped off outside the biggest contests. Michigan's Senate race ranked sixth at $46m and Florida's governor race seventh at $39m. Combined, the markets covering 345 individual House races reached $24m.

Nearly 80% of the 10-day election total came between 1 November and Election Day. Even so, elections represented 0.5% of Kalshi's record $98.2bn in October trading volume. Election Day trading in the largest single contest was lower than at least 16 NFL games managed during live play this season.

The analysis also looked at Polymarket's US platform, where sports and parlays made up 88% of trading in the 10 days ending Election Day. Over that period, politics, including elections, accounted for $72.8m, or 1.3% of total volume, while NFL moneyline contracts on their own drew $220m, about three times that figure. On Election Day, politics accounted for 4.2% of volume, against more than 84% for sports and parlays.

Data caveat: trading volume reflects the value of contracts exchanged, not the revenue the platform keeps. In contrast with traditional sports betting handle, it can exceed the amount customers actually stake, especially on long-odds parlays.

Why it matters

Affiliates and operators comparing prediction markets with licensed sportsbooks should check whether headline volume is a like-for-like measure before using it in benchmarks or partner pitches. Because volume can exceed customer stakes on long-odds parlays, it is not equivalent to handle or revenue.

The split also bears on how platforms position themselves. Kalshi has promoted its election markets as a substitute for conventional polling, but thinly traded markets are more exposed to the effect of large individual trades. Outside the top contests, volumes were small, which is likely to limit how far those prices can be treated as a reliable signal.

There is also a dispute over growth. Kalshi said in an October announcement that election trading had overtaken 2024 levels and was expanding six times faster than football trading year on year. A Bloomberg analysis found that Kalshi election trading in the before the midterms was little changed from the equivalent period before the 2024 presidential election. Anyone relying on platform-reported growth claims could need to check the underlying data.

What's next

The Polymarket figures point the same way as Kalshi's: sports and parlay products account for the large majority of activity.