Eight days before Election Day, the crowd that likes to put money where its mouth is has spoken, loudly. Prediction markets midterms trading has passed $1.4 billion in volume for the 2026 cycle, according to a CNN analysis published Oct. 23.
That is real money riding on who controls Congress. Here is the thing: the number is big, but it is not a forecast. It measures how many people are betting, and how much you should trust their odds is a separate question.
Where the $1.4 billion in midterm betting markets came from
Kalshi, the biggest U.S. prediction company, accounts for nearly $1.1 billion, according to a company spokesperson. Polymarket has more than $340 million, a spokesperson says, and that total mixes its U.S. platform with its offshore site. PredictIt declined to give dollar figures, though its co-founder said business is growing.
Those are company-reported numbers, and CNN’s full methodology is not public. Volume also is not the same as money at risk, since one dollar can change hands many times. Treat $1.4 billion as a sign of scale, not an exact tally. The same caution applies to every election prediction markets headline you will see this week.
The growth is still striking. CNN put the total above $750 million as of Oct. 15, according to iGaming Business. That is nearly eight times the $92.4 million traded on non-presidential contracts in 2024. The Anti-Corruption Data Collective projects the total could reach $1.6 billion by the end of the midterms.
What Kalshi and Polymarket odds are saying
Both the markets and the polls point toward likely Democratic gains, according to Yahoo News. One recent snapshot had Polymarket giving Democrats a 93% chance at the House and 65% at the Senate, with Kalshi at 90% and 64%. Those figures were undated, and they move daily, so check live odds before you lean on them. For the bigger picture, see what is at stake on how the midterms could reshape Congress.
One outcome worth watching is a split Congress, with Democrats holding the House and Republicans keeping the Senate. Even then, the midterm election odds describe likelihoods, not certainties. As Kalshi’s Elisabeth Diana put it, “If 20% candidates never won, the markets would be broken.” A 20% shot is not a miracle. It is a coin that lands the wrong way once in five tries.
Why prediction markets midterms odds deserve caution
So who is actually trading? Not a representative sample of voters. Dustin Gouker, an industry newsletter writer, calls the markets “a meaningful signal that provides probabilities that aggregate polls and public sentiment.” That is a fair description, and also a limit. Prediction markets midterms prices reflect traders, not the whole electorate.
Thin markets are the catch. As of Sept. 24, CNN reported the control-of-Congress markets held a combined $32 million, and many House battlegrounds had under $100,000 in volume. In a market that small, a handful of traders can swing the price. That matters if you are in a district with a sleepy race.
Texas is the exception. Texas Senate and House-control markets drew nearly $49 million of the $103.87 million traded on Kalshi and Polymarket US in the first 20 days of October, according to DeFiRate. Big money is watching our state.
The fights nobody has settled
Insider trading is the open sore. Yogonet reports that Kalshi suspended six 2026 candidates for improperly betting on their own races. It also reports that federal regulators have pledged to address insider trading. We could not confirm either item with a primary source, so treat them as reported, not established. A candidate betting on his own race is the kind of thing that makes a voter’s eyes narrow.
The legal map is also a mess. Twenty-three states ban betting on elections, per CNBC citing Pew, but whether those laws cover prediction-market trades is unclear. The CFTC says it has exclusive authority over these markets, while 44 state attorneys general argue sports contracts belong under state law. New York is suing Kalshi, and its suit also cites the company’s election contracts.
Election officials have their own worry: that betting could fuel distrust, NBC News reported in July. Suppose a market calls one side a lock and the other side wins. Some people will cry foul instead of accepting the result. That is a real risk in a close year, and it is why single-race polling, like the New York governor race polls, still matters alongside the betting lines.
What to watch in prediction markets midterms trading next
Election Day is Tuesday, Nov. 3. Trading is expected to ramp up right into it, and the markets will be judged against both the results and the polls. In 2024, the markets were among the first to point to a Trump win while polls called it a toss-up. That gave them credibility, and it also raised the bar.
Wording matters in polls too, as one Washington income tax repeal poll shows. A full disclosure for readers: CBS News uses Kalshi as a prediction-market sponsor, so some of the coverage you see comes from outlets with a stake. Keep that in mind when you read a headline that treats the odds as gospel.
My take: use prediction markets midterms prices as one more input, not as the answer. If you want to know what happens on Nov. 3, the only poll that counts is the one you can still walk into and vote in.
