Bitbank warns: account blocking for transactions with Polymarket and other prediction platforms
Japanese crypto exchange Bitbank has introduced strict measures against users found to be transferring funds related to Polymarket and other prediction market services. Since June 15, the company has officially warned clients about the risk of account suspension, citing internal compliance controls and the need to adhere to local gambling laws.
Bitbank does not reference a specific regulatory directive but emphasizes that using such platforms for financial gain may fall under Japanese law. The company stated that prediction markets, which allow trading on event outcomes—from elections to sports matches—operate outside Japan, but accessing them from within the country creates legal risks.
What are the consequences for violators?
If deposits or withdrawals from Polymarket or similar services are confirmed, Bitbank may block the account. After suspension, the user will lose access to: account login, crypto asset deposits and withdrawals, Japanese yen withdrawals, and trading. The exchange specifically emphasizes that it is not liable for any potential losses clients may incur as a result of such measures.
Context: Polymarket in the crosshairs
Japan is already listed in Polymarket's documentation as a jurisdiction with restricted access to the user interface, although the restrictions do not apply to the API. Earlier, in May, information emerged that Polymarket was exploring entry into the Japanese market and hoped to obtain regulatory approval by 2030, but strict local rules regarding online betting could complicate these plans.
Bitbank's warning is not an isolated case. In early 2026, the Portuguese regulator demanded that Polymarket cease operations in the country after the volume of bets on the presidential election exceeded €103 million. In the spring, Spain temporarily blocked the platform due to the lack of a gambling license, and Indonesia also took similar measures.
Expert opinion: Bitbank's actions are a logical step amid the global tightening of regulation for prediction markets. Japan, traditionally conservative on gambling issues, demonstrates zero tolerance for gray areas. For users, this is a signal: even decentralized platforms do not protect against local legal risks, and investors should consider that such blockades may become the norm in other jurisdictions.