Polymarket Founder Says Insider Trading Fears Are 'Outlandish And Baseless'

Polymarket founder Shayne Coplan has waved off the idea that prediction markets could corrupt sports, telling a Harvard audience that fears of game-fixing and insider trading are “outlandish and baseless.”

Coplan on Monday was responding to Jonathan Zittrain, a Harvard Law professor who pressed him on whether a college athlete could throw a game to cash a bet, invoking the 1919 Black Sox scandal.

Coplan said the comparison reaches back 106 years and does not reflect how the markets work today.

His rebuttal came down to scale. A single basketball market might carry just $200,000, sums Coplan called “immaterial” next to the leverage available in oil, equities and major derivatives.

Too little money, in other words, for rigging a game to pay off.

Coplan reserved sharper language for the incumbents, arguing the legal sportsbook model “rips off the casinos,” tracks a bettor’s history, and bans winners.

That puts him at odds with DraftKings Inc. (NASDAQ:DKNG) and Flutter Entertainment (NYSE:FLUT), which dominate U.S. betting through what he called a state-by-state “makeshift duopoly.”

A Hole In The Transparency Pitch

Coplan pointed to Polymarket’s blockchain as a check, noting every wallet and position is public for regulators to inspect. The catch is that a visible wallet means little without knowing who is behind it, which is the exact gap Spain just moved on.

The country’s gambling regulator blocked Polymarket and rival Kalshi on Tuesday, opening a probe into both for operating without licenses and citing the absence of identity verification, along with weak protections for minors and self-excluded users. The suspension may run three to four months.

Spain follows a blocking order in India last week and bans in Brazil and Indonesia in recent weeks.

Money Keeps Flowing In Despite Increasing Scrutiny

Polymarket is reportedly in talks to raise at a $15 billion valuation, while rival Kalshi recently hit $22 billion after a $1 billion round, both lifted by a CFTC ruling that treats their contracts as financial derivatives.

That investor enthusiasm is holding even as the legal ground shifts in Washington.

House Oversight Chairman James Comer has opened an investigation into insider trading on the platforms, calling the sector a “Wild West” with “no rules,” after a military official allegedly cleared $400,000 on a bet tied to US action in Venezuela.

Coplan waved off that same Venezuela episode at Harvard as “a fluke.” The DOJ has since charged the case.

Polymarket did not immediately respond to a request for comment.

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