Brazil's largest cryptocurrency exchange, Mercado Bitcoin, announced on Monday that it has suspended all deposits and withdrawals following a security incident affecting one of its systems. The company said the suspension is a precautionary measure while it works to contain the breach and restore normal operations.
In a statement posted to X, Mercado Bitcoin said the incident has been identified and contained, and that no customer data was leaked and no direct losses were incurred by users. The exchange is investigating the breach, tracing assets and coordinating with authorities. Bloomberg reported that the company intends to absorb any losses that may arise.
Scope of the breach
Mercado Bitcoin has published a list of destination addresses linked to the incident, covering Bitcoin, Ethereum-compatible networks, Solana, Stellar and Tron. Blockchain security firm Hypernative provided a preliminary estimate that suspicious transfers total more than $40 million across these blockchains, though the exchange has not confirmed that figure.
Response from Tether
Tether, which invested $20 million in Mercado Bitcoin in July, said it has frozen more than 4.5 million USDT associated with the incident.
Context of recent crypto security events
The incident follows a major theft at Binance on Oct. 29, where attackers accessed $6.3 billion in assets. Law enforcement agencies, including the FBI and U.S. Secret Service, have been involved in tracing and freezing funds related to that breach.
Mercado Bitcoin has not disclosed which system was compromised, the exact amount taken, or a timeline for reopening the platform.
