Brazil bans prediction markets

Brazil has prohibited derivatives tied to sports, politics, gaming, cultural events and social outcomes under Resolution №5,298, published by Banco Central do Brasil and the National Monetary Council, according to HackerNoon. The outlet reports that the measure has resulted in prediction-market platforms including Polymarket and Kalshi shutting down nationwide.

Regulators cited investor protection and market integrity, alongside concerns that arbitrage and speculative activity could damage investors and the public interest. The restrictions target the underlying subjects of the contracts, placing a broad range of event-based markets within their scope.

Restrictions spread across jurisdictions

According to HackerNoon, Brazil is the third Latin American country to ban prediction markets, after Argentina and Colombia. Portuguese regulators also blocked access to Polymarket earlier this year, while Polymarket’s own documentation lists more than 30 countries where the platform is blocked.

The United States presents a different regulatory conflict. HackerNoon reports that the Commodity Futures Trading Commission (CFTC) sued Arizona, Illinois, and Connecticut over state restrictions on access to platforms including Polymarket and Kalshi.

Integrity concerns extend beyond access

The report also highlights risks surrounding the information used to settle contracts. Polymarket paid $14,000 on April 6 and $20,000 on April 15 after unlikely Paris temperature outcomes coincided with unusual readings at a single Météo-France sensor at Charles de Gaulle Airport. According to HackerNoon, meteorologists ruled out a plausible natural explanation; suspected exposure to an artificial heat source remained a theory. Polymarket changed the settlement source to another airport without refunding losing participants.

Separately, HackerNoon reports that a US Army Special Forces Master Sergeant involved in planning Operation Absolute Resolve placed roughly $33,000 in Polymarket bets between December 27 and January 2 and won $409,000. The positions concerned a US invasion of Venezuela, Maduro’s removal by January 31 and Trump invoking the War Powers Act. The DOJ charged him with unlawful use of confidential government information, commodities fraud, and wire fraud.

What it means for prediction markets

• Contract scope matters: Brazil’s resolution covers multiple event categories, rather than restricting only sports or political markets.
• Access is jurisdiction-dependent: Brazil’s reported shutdowns add to restrictions in Argentina, Colombia and Portugal, while US state restrictions face a federal challenge.
• Settlement and information risks remain distinct: The temperature-market episode concerns the integrity of outcome data; the DOJ case concerns alleged misuse of confidential information. Both are relevant to assessing market credibility beyond the displayed odds.