Bitbank warns accounts may be suspended over Polymarket transfers

Bitbank, one of Japan’s largest cryptocurrency exchanges, warned on Monday that accounts could be suspended for deposits or withdrawals linked to Polymarket and other prediction market platforms, citing potential conflicts with Japanese gambling laws.

The exchange said it may restrict accounts that make deposits or withdrawals connected to prediction market services. Suspended users would lose access to account logins, deposits and withdrawals, and crypto trading.

“We will not be liable for any damages incurred by our customers as a result of the account suspension measures,” the notice stated. The exchange also urged customers to exercise caution when using external services and to avoid becoming involved in criminal activity or legal disputes.

Bitbank did not cite a specific regulatory action or government directive as the basis for the warning and did not respond to requests for comment.

The notice pointed to a legal question over whether prediction markets are classified as gambling under Japanese law. Platforms that allow users to bet on election results, sports outcomes and other future events can be treated as gambling when used for financial gain, and transfers linked to those platforms could expose users and intermediaries to legal risk.

Polymarket currently restricts access from Japan but earlier this year signaled interest in exploring expansion into the country.

Regulators in several jurisdictions have taken action against prediction-market services, and some exchanges and payments providers are increasing scrutiny of flows tied to those platforms.

For Bitbank customers, transfers identified as tied to prediction markets could trigger broad account restrictions and loss of access to funds and trading. The notice did not explain how the exchange will identify or trace transfers to specific external platforms.

Japan has not issued formal guidance specifically on prediction markets. Bitbank’s notice treats prediction-market-related activity as a potential compliance risk that may warrant account action.