Kalshi Is Half Right About Prediction Markets and Gambling

Kalshi Inc. co-founder and Chief Executive Officer Tarek Mansour has an argument why prediction markets shouldn't be regulated as gambling. Traditional sportsbooks, he argues, are "essentially a product that is designed for customers to lose." Sportsbooks profit from customer losses, making them structurally predatory. Kalshi, by contrast, operates as a peer-to-peer exchange: customers bet against each other, Kalshi takes fees from both sides, and the house has no stake in the outcome. It's a financial market, not a casino.

He's right about the business model distinction. He's wrong that it answers the regulatory question.

What Mansour is describing — a balanced book, fees on both sides, no house risk on outcomes — has been the operating model of sports betting, both legal and illegal. The genius of the operation, which reached its mature form with the invention of the point spread in the 1940s, was precisely its exchange-like structure. Bookmakers weren't gamblers; they were market makers. The business was less like the corner bookie and more like the New York Stock Exchange — minus the federal charter and the disclosure requirements.

The point spread allowed bookmakers to attract roughly equal action on both sides of any sporting event, regardless of the talent gap between teams. With a balanced book, the outcome was irrelevant to profitability. Bookmakers collected roughly 10% vigorish from losing bettors, netting approximately 5% of total action however the game went. Revenue was steady, predictable, and auditable. A bookmaking operation could be evaluated entirely by how well the book balanced and how consistent the vigorish was. This was not a cottage industry. By the 1970s it was a national market, with a single price — the Vegas line — set each week and followed from Boston to Los Angeles.

Exchange-model sports betting is not a new financial innovation. It is the mid-20th-century sports betting model, and the question of whether it benefits or harms society has never had anything to do with whether the house profits from losses. Mansour's argument — we're different from sportsbooks because we don't prey on losers — is a description of a fee structure, not a regulatory philosophy. The same fee structure ran for decades before the FBI shut it down, and nobody involved claimed it was unregulated because it was fair.

Gambling regulation historically served several purposes simultaneously, and Mansour's business-model argument addresses only one of them.