How Prediction Markets Upstaged Election Polls Ella Feldman Voters, donors and media increasingly use the betting platforms Kalshi and Polymarket to forecast election outcomes. Critics warn of new risks to democracy. To get an idea of how an election will shake out, a person might look at polling data.
Increasingly, they might also look at a candidate’s odds on a prediction market, where users place bets against each other on the outcomes of real-world events. Prediction markets have soared in popularity following a landmark 2024 court victory for Kalshi Inc., a leading platform. In short order, they have become an influential tool for predicting elections.
A growing number of media outlets feature real-time market odds in their coverage, and several have entered deals with Kalshi or Polymarket, another major platform. Prediction markets have gained a reputation in some tech-friendly circles for being more accurate than traditional election polls. This perception was burnished by markets on both major platforms predicting that Donald Trump would win the 2024 presidential election.
Mainstream polls slightly overstated support for his opponent, Kamala Harris. Though the picture is unclear, some early academic research suggests this perception is accurate for major elections. At the same time, critics say turning a civic process into the object of financial speculation poses new risks for democracy.
Here’s what’s important to know. Accounts of election betting in the US date to more than a century ago. In the early 1900s, bettors wagered on elections outside of the New York Stock Exchange, creating odds that were reported in newspapers.
The practice declined as state laws and court rulings made election betting widely illegal, and scientific polling became the favored predictive tool for elections. For decades, the Commodity Futures Trading Commission — the federal agency that regulates derivatives markets — only tolerated election-related markets, such as the Iowa Electronic Markets, that operated as not-for-profit research tools with caps on traders and individual bets. That changed in 2024, when Kalshi fought the agency’s decision to prohibit its proposal to take bets on the US congressional elections results and won, allowing it to run election markets a month before the vote took place.
The federal court’s ruling allowed Kalshi to legally run election markets, and gave the industry confidence to offer markets on outcomes in sports, entertainment and much more. (Polymarket was forced to leave the US after a settlement with the CFTC in 2022. Its primary exchange operates overseas. It has since launched a separate exchange in the US, largely limited to sports.)A boom in the prediction market industry followed.
Today, Kalshi and Polymarket users trade on everything from whether the Los Angeles Rams will win the Super Bowl to whether the federal government will confirm the existence of aliens this year. Demand determines the prices of “yes” or “no” bets, and those prices represent the market’s assessment of the probability that an event will happen. Monthly trading volume across the two platforms was $4.7 billion in November 2024, according to data from Dune Analytics.
By September 2026, monthly volume across Kalshi and Polymarket was $64.9 billion, excluding Polymarket US. (Bloomberg LP, the parent of Bloomberg News, provides Polymarket and Kalshi data to clients as part of its broader data offering.) Read More: How Prediction Markets Turned the World Into a Casino Though sports have been the primary driver of growth on Kalshi and Polymarket, sizable sums are also spent on major elections. Polymarket’s 2024 US presidential election market attracted nearly $3.7 billion in volume. The total volume of markets for congressional races in 2024 surpassed $92 million across Polymarket and Kalshi, according to an analysis by the nonprofit group Anti-Corruption Data Collective.
The 2026 congressional midterms had already generated more tha...
Source: Bloomberg Markets · Summarized by HeadlinesBriefing