USDPolymarket Faces Japan Push, Exploit Fallout and U.S. Probe
Prediction-market scrutiny widens across regulation, security and insider trading
TL;DR
- Polymarket is seeking Japan entry while remaining restricted in several jurisdictions.
- A Polymarket-linked exploit produced loss estimates ranging from at least $520,000 to about $660,000.
- U.S. House Republicans opened an investigation into Kalshi and Polymarket over insider trading risks.
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Polymarket is facing pressure on three fronts: a push to enter Japan despite strict gambling rules, a Polymarket-linked infrastructure exploit with the highest cited loss estimate at about $660,000, and a U.S. House Oversight Committee investigation into insider trading risks on prediction-market platforms.
Polymarket is reportedly seeking entry into Japan and has appointed Mike Eidlin, head of Japan at crypto firm Jupiter, to lead local efforts. The company is preparing to lobby for authorization of prediction markets and is targeting Japanese government approval by 2030, even as prediction markets face growing regulatory scrutiny across several jurisdictions.
Japan presents a difficult opening because online gambling is generally limited to select government-authorized activities such as horse racing and public lotteries. Violations tied to online casino use can carry fines of up to $3,400 and potential prison sentences of up to three years for repeat offenders.
Polymarket said it has seen “meaningful organic interest from users” in Japan and across Asia, adding that it is “always evaluating opportunities to expand access globally in compliant and locally appropriate ways.” The company already operates a Japan-focused X account with more than 53,000 followers, although it is still seeking approval to operate in the country.
Polymarket lists Japan among 35 restricted jurisdictions, including the United States, under its country access policy. Start Polymarket data showed the platform blocked in roughly 34 countries and subject to “close-only” restrictions in four additional jurisdictions. Earlier reporting cited in the source indicated some users in restricted regions may still access the platform through tools such as VPNs.
India is among the latest jurisdictions moving against prediction markets, with authorities reportedly preparing blocking orders against Kalshi after earlier action against Polymarket. Token Terminal data showed Polymarket’s monthly notional trading volume fell nearly 15% in April, while Kalshi’s rose about 13%.
Exploit Raises Infrastructure Questions
Polymarket confirmed that a security exploit affected part of its infrastructure and pointed to a possible private key compromise involving a wallet used for top-up operations. The company said user funds and market resolution were safe, while Polymarket developers said contracts and core infrastructure were unaffected.
Akanshu Jain, Polymarket product lead, and multiple other Polymarket employees also said user funds and market resolution are safe. Josh Stevens, Polymarket’s vice president of engineering, said the contracts were safe, the exploit was limited to a six-year-old private key used for internal top-up operations, and all permissions tied to that key had been revoked.
Blockchain investigator ZachXBT first flagged the incident as a compromise of the Polymarket-linked UMA Conditional Tokens Framework Adapter contract on Polygon, saying the exploiter drained at least $520,000. The UMA CTF Adapter is an oracle contract used to help resolve Polymarket prediction markets through UMA’s Optimistic Oracle, which Polymarket integrated on Feb. 3, 2022, to enable automated and decentralized market resolution.
Polygonscan data showed more than 100 small transfers into the alleged attacker wallet, with most transfers worth up to 5,000 Polygon tokens. Bubblemaps said the attacker continued removing about 5,000 POL tokens every 30 seconds and had amassed about $600,000 in stolen funds at the time of writing. Lookonchain estimated about $660,000 had been drained from the Polymarket-linked contract as of 9:01 am UTC on Friday.
DefiLlama data identified Polymarket as the world’s second-largest prediction market, with $3.7 billion in monthly trading volume.
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House Oversight Targets Insider Trading Risks
The U.S. House Oversight Committee opened an investigation into Kalshi and Polymarket, with Committee Chair James Comer, R-KY, focusing on insider trading by platform users and wagers that may rely on non-public information. Comer said, “This growing pattern of insider trading activity on prediction market platforms indicates that Congressional action may be necessary.”
Comer sent letters to Kalshi CEO Tarek Mansour and Polymarket CEO Shayne Coplan requesting records related to the companies’ internal operations. The requested documents include materials and communications tied to know-your-customer standards, suspicious-trade detection policies and procedures, analysis of reputational impact from insider-trading scandals, and internal deliberations over offering wagers linked to armed conflicts.
Comer also asked Kalshi and Polymarket to provide internal communications and documents related to wagers on the Iran war and America’s attack on Venezuela earlier this year. The congressional investigation follows the arrest of a U.S. soldier who allegedly placed Polymarket bets on the timing of American military actions using classified information.
The probe also follows Kalshi fining multiple U.S. politicians for betting on the outcomes of their own elections. Comer was also reportedly influenced by a New York Times investigation that identified more than 80 instances of potential insider trading on Polymarket.
Prediction-market scrutiny has expanded in Washington, with the Senate unanimously passing a resolution last month banning its own members and staff from trading on prediction markets. The House investigation is politically significant because it is backed by Republican committee leadership rather than Democratic lawmakers, and House Oversight Committee GOP leadership likely has the votes to issue legally binding subpoenas.
Dan Boyle, a partner at Boies Schiller Flexner and a former federal prosecutor focused on gambling-related fraud, said lawmakers may question the platforms’ enforcement posture, asking, “If they can catch this guy, why can't you catch another?” Boyle added that if prediction-market platforms argue they lack the ability to catch these issues, that is one position, but their public push to show they have detection technology and are willing to use it creates a tougher oversight problem.
FAQ
Is Polymarket approved to operate in Japan?
No. Polymarket is seeking Japanese government approval by 2030.
Were Polymarket user funds affected by the exploit?
Polymarket and company employees said user funds and market resolution were safe.
What is House Oversight investigating?
Insider trading risks and wagers that may rely on non-public information.
Who leads Polymarket’s Japan effort?
Mike Eidlin, head of Japan at crypto firm Jupiter.
This article has been refined and enhanced by ChatGPT.
