TKO Group Holdings Inc. and Polymarket Signage on the floor of the New York Stock Exchange (NYSE) in New York, US, on Thursday, November 13, 2025.
Michael Nagle | Bloomberg | Getty Images
The Iran war has shed light on what prediction markets consider unacceptable subjects for betting, as users have faced backlash when they placed hundreds of millions in bets on everything from missile strikes to regime change.
Polymarket last week archived markets that allowed bets on the timing of nuclear detonations, after the contracts attracted hundreds of thousands of dollars.
“From a nuclear weapon explosion…?” Most of the contracts fell under the heading market. According to webpages saved in the Internet Archive’s Wayback Machine, it allowed users to place a bet on whether an event would occur by a certain date.
The removal of nuclear-related markets came hours after the company posted — and later deleted — odds on X showing a 22% probability of detonation by the end of the year.
Shout out online
The bets have sparked outrage online and come as some makers propose tighter regulations and oversight of the fast-growing betting industry, which allows users to bet on the outcomes of a wide range of events.
Polymarket did not give reasons for the removal. It did not immediately respond to a request for comment from CNBC.
Over the weekend, the company’s founder and CEO, Shane Coplan, was asked at the MIT Sloan Sports Analytics Conference about some of the broader controversies surrounding futures markets regarding geopolitical conflicts like Iran.
Coplan said it’s a “complex question,” but futures markets serve a powerful information function and value proposition, including in war zones.
He dismissed some criticism as “more money, more problems”. “There’s still a lot of resistance to innovation, confusion in that kind of startup … that makes it innovative and disruptive,” he said.
The Commodity Futures Trading Commission is the main regulator of US futures markets such as Polymarket and Kalshi, where transactions on those platforms are treated as financial derivatives contracts.
PolyMarket’s main international exchange operates offshore, but the company is planning a separate CFTC-regulated US version of its platform.
US-based prediction sites such as Manifold Markets are allowing bets on a nuclear explosion as this article goes live.
CNBC did not identify such bets on large platforms such as Kalshi, a company not immune to Iran-related controversy.
Earlier, Kalshi faced backlash in the multi-million dollar market over whether Iran’s Supreme Leader Ali Khamenei would be deposed. It was later confirmed that he was killed in the first wave of Israeli and US airstrikes on 28 February.
The company eventually issued a refund on the market, citing rules restricting bettors on death.
In a statement to CNBC, Kalshi said “markets are not allowed to be tied directly to death.”
Last week, Sen. Chris Murphy (D-Conn.) and Rep. Mike Levin (D-Calif.) proposed a bill that would restrict or ban markets that settle on military actions, regime change, or deaths that promote conflict or reward access to classified information.
Insider trading concerns
US lawmakers have suggested that markets allow for insider trading and corruption.
Such concerns have long surrounded the futures market boom, with some lawmakers accusing Kalshi and Polymarket of allowing well-connected bettors to profit on non-public information.
Senators Merkley and Klobuchar last week introduced the End Prediction Market Corruption Act, which would bar the president, vice president, members of Congress and their immediate families from trading event contracts on prediction platforms.
The measure imposes fines and profit clawbacks for violations, citing timely bets on US strikes and changes in Iranian leadership that have netted some traders hundreds of thousands of dollars.
It comes after crypto-analytics firm BubbleMaps identified “six suspected insiders” who made a $1.2 million bet that the US would attack Iran. A single multi-outcome forecast market on the timing of strikes is Feb. The Polymarket, which happened on 28, raised half a billion dollars in bets.
However, Merkley and Klobuchar’s bill has no Republican co-sponsors, and GOP lawmakers in Congress have yet to signal their support for such proposals.
Disclosure: CNBC and Kalshi have a commercial relationship that includes client acquisition and minority investment.
— CNBC’s Garrett Downs contributed to this report
