TLDR
- Kalshi traded $4.15 billion on Election Day, its busiest weekday on record.
- The total stayed below the $5.3 billion record set on Saturday, Oct. 24.
- Parlay-style combos fell to 58.6% of volume, their lowest share since at least Oct. 10.
- Texas’ Senate race led all election markets at $108.1 million.
- Kalshi and Polymarket both settled House and Senate control for Democrats on Nov. 4.
Kalshi recorded $4.15 billion in notional volume on Tuesday, Nov. 3, the day of the U.S. midterm elections. The figure comes from the exchange’s daily market data and is its busiest weekday on record.
The total still fell short of the $5.3 billion record set on Saturday, Oct. 24. It also trailed the $4.79 billion traded a week later on Saturday, Oct. 31.
Election Day volume was 50.5% higher than the previous Tuesday, Oct. 27, when Kalshi traded $2.76 billion. Kalshi’s daily reports run on U.S. Eastern time.
Single Contracts Carried Election Day
What traders bought stood out more than the total. Single-market contracts, rather than bundled bets, drove the activity.
Combos are Kalshi’s parlay-style contracts, which bundle several outcomes into one. They had powered most of the exchange’s earlier daily records, and many were long shots priced below 1 cent.
On Election Day, combos accounted for $2.43 billion, or 58.6% of volume. That compares with 75.5% on Oct. 24 and 73.9% on Oct. 31, and it was the lowest share of any day since at least Oct. 10.
Trading outside combos came to about $1.72 billion. That was roughly a third more than the $1.30 billion on Oct. 24 and the highest of any day since at least Oct. 10.
Notional volume counts each contract at its full $1 payout. The buyer and seller fund that payout between them based on the price, so the figure is not the amount traders put at risk.
Texas’ Senate race was Kalshi’s busiest election series at $108.1 million. House control followed at $99.8 million, then the Texas governor’s race at $88.6 million.
Senate control drew $82.8 million, and Kalshi’s combined balance-of-power market drew $60.8 million. The five series together totaled about $440 million.
Kalshi’s 15-minute bitcoin contracts still out-traded every single election series. Those contracts saw $332.6 million in volume on the day.
How Kalshi and Polymarket Settled Congress
Over their lifetimes, Kalshi’s contracts on Democrats winning the House and Senate traded about 49.1 million and 32.4 million contracts. Polymarket, which also counts volume on a notional basis, drew about $63.3 million on its House control event and $31.5 million on its Senate control event. Its balance-of-power event drew about $75.3 million.
Both platforms had favored Democrats to win both chambers heading into the vote. Kalshi settled Senate control for Democrats at 05:46 UTC on Wednesday, Nov. 4, and House control 16 minutes later.
Polymarket resolved its Senate and House control markets for Democrats by early afternoon UTC on Nov. 4. Its 2026 midterm balance-of-power market was still awaiting resolution, with a Republican sweep priced below 1 cent.
That leaves one Polymarket account on track to lose its stake. The account bet about $183,000 on Republicans keeping both chambers.
Front Office Sports reported before the vote that lawmakers in both parties were pushing bills on sports event contracts, insider trading, and war markets. Those include the Prediction Markets Are Gambling Act from Sens. Adam Schiff and John Curtis.
Experts told the publication a Democratic Congress could call Kalshi and Polymarket to hearings. It could also use spending bills to limit what the CFTC spends on litigation or new rules, though any bill restricting the platforms could face a veto from President Donald Trump.
