Bettors have long been able to speculate on the chance of a nuclear weapon detonating on Polymarket, but the current conflict with Iran – and scrutiny about insiders trading on war – has apparently caused the platform to remove the contracts.

The markets, which asked users to assign probabilities to whether a nuclear weapon would detonate by specific dates, have circulated on Polymarket for years and historically have resolved to “No.”

But renewed attention to the contracts comes as prediction markets face criticism after a trader reportedly made more than $400,000 betting on Venezuelan leader Nicolás Maduro’s ouster shortly before the U.S. operation that led to his capture, raising questions about whether insiders could exploit the platforms to trade on the outbreak of war – such as the start of this current conflict with Iran – and other military actions.

Historical trading suggests the contracts occasionally priced meaningful risk.

A Polymarket contract in 2023 at one point implied roughly a 19% chance that a nuclear weapon would detonate before the end of the year, according to platform data.

A later market expiring in June 2025 traded near 12%.

The markets also attracted significant trading activity. The 2025 contract alone recorded more than $1.7 Million in volume, while the 2023 version drew nearly $700,000 in wagers.

All this comes as U.S. regulators consider how to oversee prediction markets.

The Commodity Futures Trading Commission proposed rules in 2024 that would bar exchanges it regulates from listing event contracts tied to war, terrorism, assassination, or other activities deemed contrary to the public interest.

Chairman Mike Selig said the Commission plans to issue clearer guidance on prediction markets in the near future.