South Korea's Broadcasting Media and Communications Review Committee has decided to block access to the overseas prediction market platform Polymarket after judging it constitutes illegal gambling and speculative activity under domestic law.

The committee said it held a communications review subcommittee meeting on Aug. 18 and voted for a corrective order, including blocking access. It said it judged Polymarket to fall under information aimed at aiding gambling or opening a gambling venue under the Criminal Act, and information aimed at similar acts under the National Sports Promotion Act.

The committee said it decided at a communications subcommittee meeting on July 6 to hear Polymarket's views. It said it confirmed the platform's position on Aug. 18 and made a final decision.

Polymarket is a prediction market platform where users trade on the outcomes of events beyond their control, including politics, the economy, international relations, sports, elections and the weather.

The committee judged that Polymarket's winner-takes-all profit-and-loss structure, in which financial gains and losses diverge sharply depending on outcomes, encourages gambling tendencies.

It also considered that Polymarket's operator runs and manages the platform overall, including opening markets and setting trading rules. It said the operator provides a virtual asset deposit, withdrawal and settlement system that creates an environment in which user funds are effectively collected and disbursed, while earning economic benefits through fees from share trading.

Earlier, the committee said it gathered views from related agencies including the National Police Agency, the National Gambling Control Commission and the Korea Sports Promotion Foundation. Those agencies presented opinions that Polymarket's operating 방식 could fall under opening a gambling venue or gambling offences under domestic law.

Polymarket argued in its statement that it is not subject to the Information and Communications Network Act, citing steps including removing Korean-language services on its platform and not supporting payments in won.

It also argued that the platform operates through non-custodial peer-to-peer (P2P) trading and smart contracts, meaning it does not qualify as an operator. It said it does not directly handle or manage funds or issue sports promotion voting tickets, and therefore does not meet requirements for violations under the Criminal Act and the National Sports Promotion Act or for speculative activity.

The committee, however, judged that domestic laws cannot be avoided on grounds such as whether Korean-language services are provided, decentralised technology or technical characteristics or service methods such as a trading interface.

It said trading is taking place on domestically specific issues such as August rainfall in Seoul. It said blocking access was unavoidable because the platform provides domestic users with a practical environment for illegal gambling based on a winner-takes-all profit structure driven by chance.

France blocked access to Polymarket from July 16, citing concerns it could cause users massive losses and that some betting could be manipulated. Australia and Germany have also blocked access to Polymarket, judging it to be an illegal online gambling service or betting not permitted under law, in August and September 2025, respectively.