Kalshi and Polymarket are now clearing something like $24 billion in trades a month, more than the country’s licensed books handle. The matchup is messier than the headline suggests, but the scramble by states to tax it is not.
- Pew Research Center puts the two big platforms, Polymarket and Kalshi, at roughly $24 billion in combined monthly trades as of April 2026, a nearly fivefold jump from the previous fall
- Licensed U.S. books, by contrast, took in somewhere near $14 billion a month across 2025, though the two yardsticks are not measuring the same thing
- Because the exchanges answer to the federal CFTC rather than state gaming boards, they reach residents of Texas and California, both off-limits to sportsbooks, and skip state betting taxes entirely
- North Carolina and Kentucky have broken from the pack by taxing the operators directly, a different tack than the court fights and prohibitions tried elsewhere
- Sports drives close to 80 percent of what changes hands on Kalshi, which is exactly why the books and their regulators are uneasy
The pecking order of American betting just got turned around. Month over month, the dollars moving through prediction markets have pulled ahead of everything the country’s legal books take in. But the eye-catching figure hides some fine print, and the battle it has kicked off is barely underway.
Prediction Market Volume Blew Past the Sportsbooks
Pew Research Center laid out the trajectory, and it is steep. As recently as September 2025, Polymarket and Kalshi together saw under $5 billion change hands in a single month. By April 2026 that tally sat near $24 billion, almost five times larger across a span of eight months. Set it beside the roughly $14 billion a month that flowed through the nation’s licensed books in 2025 and the picture is startling: a category most people could not have named two years ago is suddenly pushing around more cash than the whole legal wagering business.
The Catch Behind the Comparison
Before anyone writes the sportsbook’s obituary, the numbers reward a closer read. That $24 billion is a worldwide tally, and the bulk of it has nothing to do with betting inside the United States. Polymarket’s overseas platform, which Americans can only reach through a side door, rang up around $9 billion, while its U.S.-sanctioned version managed a mere $1.3 billion. A second wrinkle matters just as much. Handle, the measuring stick for a sportsbook, counts money placed. Exchange volume counts something looser: buy a contract, unload it later, and both ends land in the total, so active traders flipping positions puff the number up. Pew says plainly that the figure can be sliced more than one way. The upshot is that the exchanges are booming and genuinely do crowd the sportsbooks, yet a fair one-to-one contest sits far tighter than $24 billion against $14 billion lets on.
The Rocket Fuel Behind the Surge
None of this happened by luck. Through the Commodity Futures Trading Commission, Washington treats prediction markets as event contracts, cousins to futures on crude oil or interest rates, rather than as gambling, and that label unlocks all fifty states. Critically, it opens the door in Texas and California, the two most populous states in the country, where a conventional sportsbook cannot legally set up shop, so someone in Dallas or Los Angeles can take a position on a game they could never wager at a book. The economics cut a different way, too. A sportsbook wins or loses on the result; an exchange just skims a fee off every transaction, so its take grows with activity no matter which side of a trade comes in.
A Gap in the Tax Code
That federal footing carries a money advantage that has state treasuries irritated. A book in a high-rate state can surrender as much as 51 cents on every revenue dollar, the going number in New York, while an exchange owes nothing in gaming tax and answers only for ordinary corporate income. Two operators can clear the exact same revenue on the exact same contest and keep wildly different sums once the state takes its cut. To lawmakers watching customers drift from taxed books toward untaxed exchanges, that spread reads like revenue strolling out the door.
From Courtroom to Cash Register
For a year the state playbook ran on cease-and-desist orders, lawsuits, and outright prohibitions. A new lane has opened. Kentucky, back in April 2026, slapped a 14.25 percent excise on the operators’ fees, the first time any state reached past the standard corporate rate to tax them, and the courts are now chewing on it. North Carolina has picked up the thread, folding a 6 percent charge on net trading-fee revenue into its latest budget and, for the first time anywhere, actually blessing the platforms instead of swinging at them. The hardball route has not gone away, mind you. Kalshi is staring down criminal counts in Arizona, and a ban in Minnesota is slated to switch on this August.
Who Ends Up Writing the Rules
Hanging over the whole thing is the question of final say. The CFTC has floated a rulebook that would wave through plenty of sports event contracts while probably shutting out casino-style games, bets keyed to officiating, markets built on player injuries, and the most prop-shaped wagers, ESPN reported. Meanwhile Kalshi is swatting away a stack of lawsuits, a cluster of states is squaring off with the CFTC over who is even in charge, and most legal watchers figure the crash between federal commodities law and state gambling statutes ends up at the Supreme Court before anyone calls it settled.
The Soft Spot in the Model
The very trait that gives these markets their punch, contracts pinned to hair-thin outcomes, is also where they bleed. In an episode that rattled regulators, a U.S. special forces soldier was accused of trading on classified details of a mission to grab Venezuela’s Nicolas Maduro, then riding a Polymarket position past $400,000 before charges caught up; he has entered a not-guilty plea. What unsettles analysts is that a bet tied to one narrow event invites the same rigging that surfaced in the recent MLB and NBA prop cases, which keeps the spotlight on integrity every bit as much as on tax dollars.
Where This Is Headed
For the moment the exchanges hold the high ground on both fronts, volume and taxes alike, and the North Carolina and Kentucky levies are really states trying to win back revenue without betting on a lawsuit they might lose. Whether that template catches on, or whether judges and federal regulators redraw the lines first, is the part nobody can call. What is past arguing is that prediction markets have grown from a curiosity into a real rival, one that neither the books nor the statehouses can afford to wave off.