Bitbank, a major Japanese cryptocurrency exchange, announced on June 15 that users transacting with prediction market platforms like Polymarket face immediate account suspension. The reason: Japan's strict gambling laws. The move puts a chill on the growing prediction market sector in one of Asia's most regulated crypto markets.
Why the law applies
Japan forbids most forms of gambling. Prediction markets, where users bet on outcomes of events — elections, sports, even pop-culture moments — can fall under that ban when real money is at stake. Bitbank's statement this week made that connection explicit. Users who engage with such platforms are now flagged as violating the exchange's terms of service. No warning. No grace period.
What users see
The suspension is immediate upon detection. That means a user's account is frozen, funds are locked, and trading stops. Bitbank didn't specify how it identifies offenders — whether by monitoring on-chain activity, wallet addresses, or API data. But the consequence is clear: access to the exchange is gone. For Japanese crypto traders, that's a serious risk.
A first for Japanese exchanges
Bitbank is the first major exchange in Japan to take a public stand against prediction markets. The action signals that regulators may be tightening oversight of platforms like Polymarket, which operates from outside the country but still serves Japanese users. Other exchanges in Japan haven't announced similar policies yet, but Bitbank's move could set a precedent. The timing isn't great for the prediction market industry, which has seen rapid growth this year.
Polymarket itself hasn't responded publicly to the suspension policy. The company faces an uncertain regulatory environment across several jurisdictions. For now, Japanese users have a clear choice: stay off prediction markets or risk losing their exchange accounts. It's a blunt message — and one the rest of the industry is watching.
