How Prediction Markets Work—and Why They're Controversial
Prediction markets let traders bet real money on future events, from elections to economic data. Here's how they work, who regulates them, and why they're sparking legal battles.
Betting on the Future, One Contract at a Time
Prediction markets are exchanges where people buy and sell contracts tied to the outcome of real-world events—elections, economic reports, weather, even Oscar winners. Unlike traditional stock markets, where you buy a piece of a company, prediction markets let you wager on whether something will happen. If you're right, you profit. If not, you lose your stake.
Once an academic curiosity, these platforms now move hundreds of millions of dollars. They've outperformed polls in forecasting elections and are drawing attention from Wall Street, Silicon Valley, and federal prosecutors alike. But as prediction markets grow, so do the questions about where finance ends and gambling begins.
How the Mechanics Work
Every prediction market contract is a binary bet. A contract pays $1 if the specified event occurs and $0 if it doesn't. The current trading price—somewhere between $0.01 and $0.99—reflects the crowd's estimated probability. A contract priced at $0.63 means the market collectively believes there's a 63% chance the event will happen.
Traders who think the probability is underpriced buy; those who think it's overpriced sell. As new information emerges—a surprise poll, an earnings report, a policy announcement—prices shift almost instantly. This makes prediction markets a kind of real-time probability engine, aggregating the knowledge and hunches of thousands of participants into a single number.
The mechanism mirrors financial derivatives. In fact, prediction market contracts are legally classified as event contracts, a type of binary option regulated under the Commodity Exchange Act (CEA).
Who Runs Them
Two platforms dominate. Kalshi, founded in 2021, is the only prediction market fully regulated by the U.S. Commodity Futures Trading Commission (CFTC) as a designated contract market (DCM). It operates like a traditional exchange, offering contracts on economics, weather, politics, and sports.
Polymarket, by contrast, runs on the Polygon blockchain and uses the stablecoin USDC. It has attracted massive global volume—particularly around elections—but operates in a regulatory gray zone, having previously settled with the CFTC for operating without proper registration.
The original modern prediction market, the Iowa Electronic Markets, launched at the University of Iowa in 1988 as a research tool. The CFTC granted it a no-action letter in 1992, allowing it to operate on a not-for-profit basis—planting the regulatory seed for everything that followed.
The Regulatory Tug-of-War
The central legal question is deceptively simple: are prediction markets financial instruments or gambling? The answer determines whether they fall under federal CFTC oversight or state gaming laws.
The CFTC claims exclusive federal jurisdiction. Under the Dodd-Frank Act of 2010, Congress gave the agency authority to prohibit event contracts it deems contrary to the public interest, including those involving terrorism, war, or certain gaming activities. But the boundaries remain fuzzy.
Some states disagree with federal preemption entirely. Arizona filed criminal charges against Kalshi, alleging it operates an illegal gambling business. Meanwhile, a federal appeals court ruled in Kalshi's favor in a separate New Jersey case—the first appellate-level victory for the industry—reinforcing the view that these are regulated financial products, not casino bets.
Insider Trading on the Future
The biggest emerging concern is information asymmetry. If a politician bets on their own election, or a government official trades contracts on a policy decision they'll help make, the parallels to securities insider trading are obvious.
Federal prosecutors in Manhattan have begun exploring whether existing insider trading and fraud statutes apply to prediction market activity. Lawmakers from both parties have introduced the Public Integrity in Financial Prediction Markets Act, which would ban elected officials, political appointees, and congressional staff from trading contracts related to government policy or political outcomes while holding material nonpublic information.
Kalshi itself has taken enforcement action, suspending three political candidates who bet on their own races and imposing fines—the most aggressive self-policing the industry has seen.
Why They Matter
Supporters argue prediction markets produce more accurate forecasts than polls or expert panels because they force participants to put money behind their beliefs, filtering out noise and bias. Critics counter that they commodify democracy, turning elections into spectator sport and creating perverse incentives for manipulation.
What's clear is that prediction markets aren't going away. The question is whether regulators can build a framework fast enough to keep up with an industry that, by its very nature, is always one step ahead of the present.
