Binance said at least $2.54 billion in funds were frozen following a “potential security issue” and that it suspended all deposits and withdrawals as a precaution while it investigates the case, according to Al Jazeera.

Founder Changpeng Zhao said the episode looks like a hack on the exchange, according to Al Jazeera, and Tether and Circle said they froze funds in response to the incident, according to The Guardian.