South Korean police are investigating 26 individuals suspected of placing illegal bets worth approximately 19 billion won ($12.7 million) through the crypto prediction platform Polymarket, according to local media reports on September 17. The Seoul Metropolitan Police Agency's Financial Crime Investigation Unit is examining activity allegedly conducted between January 2024 and June 2026, involving more than 4,000 transactions. Individual trading volumes reportedly ranged from tens of millions of won to several billion won.
Investigators are looking at potential violations of South Korea's Criminal Act provisions on gambling and habitual gambling. No convictions have been announced, and the users under investigation are not considered to have committed an offence unless allegations are established through legal proceedings. Under Article 246, gambling can carry fines up to 10 million won, while habitual gambling can result in imprisonment of up to three years or a fine of up to 20 million won.
Polymarket lets users trade contracts whose prices reflect expectations about future events, generally denominated in USDC, with outcome shares settling at $1 if an event occurs and $0 otherwise. South Korean authorities can treat wagering on uncertain events for financial gain as gambling even when the service describes itself as a prediction market and uses cryptocurrency instead of conventional money.
The probe follows earlier scrutiny of offshore prediction platforms. In 2025, South Korea's National Police Agency said it was reviewing Polymarket and Kalshi as part of efforts to combat illegal online gambling. Polymarket has expanded its global profile since the 2024 U.S. presidential election and acquired CFTC-regulated derivatives exchange QCEX for $112 million in 2025, but that U.S. regulatory status does not automatically authorize the platform elsewhere.
South Korea has also reported broader retail financial fraud losses. Police investigated 3,506 stock-tip chatroom cases involving 336 billion won in the first half of 2026, with money involved up 19.8% year over year. Authorities say fraudsters used fake brokerage apps, fabricated success stories, and AI-generated investment claims to target investors. Financial regulators have launched a nationwide fraud-prevention campaign running through the end of 2026, while police are strengthening platform detection systems with companies including Naver and Kakao.
