Foreign Investors Lament Huge Losses in an Instant as Oh Sehoon Overtakes Jeong Wonoh in Seoul Mayoral Election Bets

Polymarket Offers Prediction Betting on Korean Local Elections

Extreme Volatility as Oh Sehoon Overtakes in Tight Race

On the morning of June 4, as the votes for the June 3 Seoul mayoral election were being counted, thousands of foreign investors lost tens of billions of won in an instant when Oh Sehoon, the People Power Party candidate, overtook Jung Wonoh, the Democratic Party of Korea candidate, by a narrow margin. This all took place on the American prediction market platform, Polymarket.

Polymarket, which offers prediction services for outcomes of all kinds of events happening around the world, also provided betting opportunities on the winners of this local election. In particular, the Seoul mayoral race, which was extremely close, saw record-breaking trading volumes. Some critics are raising concerns that Polymarket is essentially facilitating illegal gambling.

Foreign Investors Betting on Korean Election Results on Polymarket

Prediction trend results related to the Polymarket Seoul mayoral election. Polymarket capture

As of June 4, the total trading volume on Polymarket for the Seoul mayoral election reached 50.39 million dollars (approximately 7.7 billion won). That morning, around 7 a.m., the probabilities for Oh and Jung’s victory experienced a sudden fluctuation. When Oh Sehoon narrowly surpassed Jung Wonoh’s vote share, his probability of winning surged from 45% to as high as 887% in an instant.

The asset values of Polymarket investors, whose "betting amounts" change according to the probability of victory, also experienced dramatic ups and downs. The comments section was flooded with investor reactions such as "Update the counting results quickly," "This is a scam," and "Thanks to this, I made a lot," creating a chaotic scene.

On Polymarket, the prediction market platform, users can place bets on election results from numerous countries, including the United States, Europe, Korea, and Japan. The Seoul mayoral election drew enormous global attention even before the vote counting began, with some accounts identified as placing bets worth 170,000 dollars (about 260 million won) at once. The world’s largest English-language online community, Reddit, also saw heated debates among users over the election results.

Ongoing Controversy Over Illegal Gambling

Controversy is growing over whether Polymarket is a form of gambling. Polymarket capture

Although interest in Polymarket among online users is growing, some argue that it is essentially no different from illegal gambling. There is also an ongoing controversy over the use of insider information to manipulate prediction prices. Previously, in April, a U.S. Army Special Forces master sergeant was indicted for using confidential information related to the arrest of Venezuelan President Nicolas Maduro to bet on a related prediction on Polymarket, making 400,000 dollars (about 600 million won).

In Indonesia, when a bet was opened on whether the president would resign early, the local authorities decided to completely block citizen access to Polymarket, classifying it as a form of online gambling.

On May 22, the Korea Communications Standards Commission reportedly began reviewing whether Polymarket violates domestic gambling laws. Under current law, any betting activity outside of Sports Toto (with a maximum limit of 100,000 won), operated by the Korea Sports Promotion Foundation, is illegal in Korea.

Nevertheless, participant interest in prediction markets remains high. This year, the combined cumulative trading volume of major prediction market platforms such as Polymarket and Kalshi has nearly reached 39 billion dollars (about 58 trillion won).

This content was produced with the assistance of AI translation services.