The Gaming Regulation and Inspection Service (SRIJ) of Portugal has ordered the immediate shutdown of prediction market operator Polymarket, citing violations of national laws prohibiting political betting.
The decision follows highly unusual trading activity during the country’s recent presidential election, where odds shifted drastically in the hours before official results were public.
€4 Million Surge Before Polls Closed
According to the SRIJ, over €4 million was staked in the final hours of the election, coinciding with the circulation of private exit polls. Data reported by Renascença showed that odds for candidate António José Seguro jumped from 60% to 96% between 5:00 PM and 6:00 PM, a full hour before polls officially closed. Meanwhile, rival Cotrim de Figueiredo saw his odds collapse from 22% to just 2.5% during the same window.
Regulators concluded that “leaked information” likely fueled the trading rush, which saw total volumes hit €5 million between 6 PM and 8 PM. “The website is not authorized to offer betting in Portugal, and under national law, betting on political events or happenings, whether national or international, is not permitted,” the regulator stated in its ruling.
Global Pressure Mounts on Polymarket
Polymarket, which processed over $103 million on the main presidential market alone, now joins a list of banned platforms in Portugal. The SRIJ has instructed network providers to block access to the site after it failed to comply with an initial 48-hour shutdown order.
This ban adds to Polymarket’s growing international challenges. The platform is already restricted in France, Australia, and the UK, and faces legal scrutiny in the U.S. regarding insider trading risks. Despite these regulatory hurdles, Polymarket reported a 28% increase in political betting in December 2025, with total wagers exceeding $4.3 billion.
