Key Takeaways
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Kalshi’s Election Day volume was $4.15 billion on Nov. 3, below its $5.3 billion record from Oct. 24. -
Combos made up 58.6% of Election Day volume, against 75.5% on Oct. 24 and 73.9% on Oct. 31. -
The five largest election series, led by Texas’ Senate race, traded about $440 million on the day.
Kalshi Election Day Volume vs. the Oct. 24 Record
Kalshi recorded $4.15 billion in notional volume on Tuesday, Nov. 3, the day of the U.S. midterm elections, according to the exchange’s daily market data for Nov. 3. That was below the record $5.3 billion traded on Saturday, Oct. 24, and the $4.79 billion traded a week later on Saturday, Oct. 31.
It was still Kalshi’s busiest weekday in its daily data. Election Day volume was 50.5% above the previous Tuesday, Oct. 27, when Kalshi traded $2.76 billion. Kalshi’s daily reports run on U.S. Eastern days.
Why Did Combos Fall to 58.6% of Kalshi’s Election Day Volume?
Combos are Kalshi’s parlay-style contracts, which bundle several outcomes into one. They had driven most of Kalshi’s earlier daily records, many of them long shots priced below 1 cent. On Election Day, combos accounted for $2.43 billion, or 58.6% of volume, down from 75.5% on Oct. 24 and 73.9% on Oct. 31. That was the lowest share of any day since at least Oct. 10.
Trading outside combos did the lifting. It came to about $1.72 billion on Election Day, about a third more than the $1.30 billion on Oct. 24, and more than on any other day since at least Oct. 10.
Notional volume counts each contract at its full $1 payout, which the buyer and seller fund between them according to the price. It is not the amount traders put at risk.
Texas Senate Race Led Kalshi’s Election Markets
Texas’ Senate race was Kalshi’s busiest election series of the day at $108.1 million. House control followed at $99.8 million, then the Texas governor’s race at $88.6 million, Senate control at $82.8 million, and Kalshi’s combined balance-of-power market at $60.8 million. Those five series totaled about $440 million. Kalshi’s 15-minute bitcoin contracts still traded more than any single election series, at $332.6 million.
Over their lifetimes, Kalshi’s contracts on Democrats winning the House and the Senate traded about 49.1 million and 32.4 million contracts, respectively. Polymarket counts volume on a similar notional basis, and its House control event had drawn about $63.3 million, its Senate control event about $31.5 million, and its balance-of-power event about $75.3 million.
Kalshi settled Senate control for Democrats at 05:46 UTC on Wednesday, Nov. 4, and House control 16 minutes later. Both Kalshi and Polymarket had favored Democrats to sweep Congress going into the vote.
Polymarket had resolved its Senate and House control markets for Democrats by early afternoon UTC on Nov. 4. Its balance-of-power market for the 2026 midterms was still awaiting resolution, with a Republican sweep priced at less than a cent. That puts a Polymarket account that bet about $183,000 on Republicans keeping both chambers on course to lose it.
The results could also bring more pressure on prediction markets in Washington. Front Office Sports reported before the vote that lawmakers in both parties were already pushing bills on sports event contracts, insider trading, and war markets, including Sens. Adam Schiff and John Curtis’s Prediction Markets Are Gambling Act.
Experts told the publication that a Democratic Congress could call Kalshi and Polymarket to hearings, and use spending bills to limit what the CFTC can spend on litigation or new rules. Any bill restricting the platforms would still face a possible veto from President Donald Trump.
