Zondacrypto's 4,500 BTC sat in a wallet only a missing founder could open

Zondacrypto, Poland's largest crypto exchange, operated through an Estonian entity, BB Trade Estonia OÜ. Withdrawal delays began around 7 April 2026; the CEO promised normalisation within days. On 16 April, chief executive Przemysław Kral released a recording meant to prove solvency: a cold wallet holding about 4,500 BTC, roughly $330 million. It backfired — he admitted the private keys were held by co-founder Sylwester Suszek, who had stepped down in May 2021 and disappeared in March 2022. The exchange had not been able to move that wallet since 2022.

The next day, 17 April, the Regional Prosecutor's Office in Katowice opened an investigation into large-scale fraud and money laundering, with damages estimated at no less than PLN 350 million and several hundred victims; prosecutors put customer losses above $100 million. Wallets linked to the exchange had lost about 99% of their balances since mid-2024, and filings revealed a €75 million unsecured crypto loan to clients. On 19 April the entire supervisory board resigned and staff salaries were suspended; Kral later left Poland for Israel, where he holds citizenship.

The custody failure had been hiding in plain sight for four years: an exchange can advertise reserves it cannot move, until the day customers ask to withdraw.