Brazil bans prediction markets

Brazil has prohibited derivatives tied to sports, politics, gaming, cultural events and social outcomes, prompting Polymarket and Kalshi to shut down nationwide, according to HackerNoon. The move makes Brazil the third Latin American country to ban prediction markets, after Argentina and Colombia.

A broad restriction on event contracts

Banco Central do Brasil and the National Monetary Council issued Resolution №5,298, which establishes the prohibition, HackerNoon reported. Regulators cited investor protection, market integrity and concerns that arbitrage and speculation could damage investors and the public interest.

The decision adds to restrictions facing prediction-market operators across jurisdictions. Portuguese regulators blocked access to Polymarket earlier this year, according to HackerNoon. The platform’s own documentation lists more than 30 countries where it is blocked.

The United States presents a different regulatory conflict. Individual states have sought to restrict prediction markets, while the Commodity Futures Trading Commission (CFTC) has sued Arizona, Illinois, and Connecticut over restrictions on access to platforms including Polymarket and Kalshi, HackerNoon reported.

Integrity concerns extend beyond access

The report also describes questions about the reliability of settlement data. Polymarket paid $14,000 on April 6 and $20,000 on April 15 after bets on Paris temperatures exceeding specified thresholds. Both payouts followed unusual readings at a single Météo-France sensor at Charles de Gaulle Airport. Meteorologists considered natural explanations implausible; external heating, possibly from a cordless hair dryer, was the leading theory. According to HackerNoon, Polymarket changed the airport used for settlement rather than refunding losing participants.

A separate case concerns alleged misuse of confidential information. HackerNoon reported that a US Army Special Forces Master Sergeant involved in planning Operation Absolute Resolve opened a Polymarket account in December, 2025. Between December 27 and January 2, he placed roughly $33,000 in bets on a US invasion of Venezuela, Maduro’s removal by January 31 and Trump invoking the War Powers Act, winning $409,000. After Trump announced the capture of Venezuelan leader Nicolás Maduro, the soldier allegedly sought to delete his account, saying he had lost email access. The DOJ charged him with unlawful use of confidential government information, commodities fraud, and wire fraud.

What it means for prediction markets

• Brazil’s restriction reaches multiple contract categories. The prohibition covers political and social outcomes as well as sports, gaming and cultural events.
• Access rules remain jurisdiction-specific. Brazil joins Argentina and Colombia in banning prediction markets, while US federal and state authorities are contesting regulatory control.
• Settlement integrity is a separate risk. The reported Paris temperature episode highlights how a contract’s outcome can depend on the vulnerability of its underlying data source.
• Information advantages face legal scrutiny. The DOJ case concerns alleged use of confidential government information—not merely a successful forecast.