Published on: January 20, 2026, 06:47h.
Updated on: January 20, 2026, 06:47h.
- Seguro claims initial lead; Ventura in second; Portugal heads to runoff
- Polymarket odds for Seguro skyrocketed pre-results, prompting speculation on leaks
- SRIJ labels Polymarket illegal locally and has instructed it to cease operations
Portugal has become the most recent region to order Polymarket to stop its operations. The prediction market, which had previously been relatively unnoticed in the country, gained significant attention following substantial trading activities in the hours leading to the announcement of its general election results on Sunday.
Over €4 million ($4.3 million) was placed on Polymarket’s presidential markets during this brief period, according to Portuguese broadcaster Renascença, leading to worries that bets may have been influenced by leaked exit polls or other confidential information.
In the end, opposition Socialist Party candidate António José Seguro emerged at the forefront with 31%, followed closely by the far-right Chega candidate André Ventura, who garnered 24%. Neither candidate achieved the required 50% to claim an outright victory.
This scenario means the election proceeds to a second round, or “run-off,” with only the top two candidates eligible to participate.
Unexpected Surge for Seguro
On election day, Seguro’s implied probability on Polymarket opened at around 60% in the early afternoon. By 6 p.m., just one hour before polls closed, his odds soared to nearly 95%. Following the circulation of exit-poll estimates, but prior to the announcement of official results, those odds nearly reached 100% certainty on the platform.
Currently, there is no indication of insider trading. Exit-poll projections began to circulate around the same time as the odds shifted, suggesting the market was simply reacting as markets do: quickly processing new information. Whether this information was shared appropriately remains a topic for Portuguese authorities.
Portugal’s gambling regulator, SRIJ, confirmed that it has ordered the cryptocurrency-based platform to halt its activities, stating that it violates national laws that restrict online gambling to licensed sports betting, casino games, and horse racing—excluding political event markets. The regulator noted that it had only recently become aware of Polymarket’s operations.
Increased Scrutiny on Prediction Markets
Portugal joins a growing number of jurisdictions examining political prediction markets functioning outside established gambling and financial structures. Polymarket has faced regulatory issues in other regions as well, including the US, where it reached a settlement with the Commodity Futures Trading Commission (CFTC) in 2022 over unregistered event-based contracts and agreed to prohibit US users.
Before the recent US presidential election, the CFTC also took legal action against competitor platform Kalshi, aiming to prevent it from offering election outcome contracts, arguing that such markets violate US commodities law. A federal court chose not to grant the requested relief.
Both Polymarket and Kalshi defend their election markets, asserting that they provide valuable insights for predicting political results and managing political risk. Critics argue that these offerings amount to gambling under a different guise and express concerns that they could erode public trust in the electoral process.