Mercado Bitcoin, Brazil’s largest cryptocurrency exchange, says its customers will not bear the cost of a hack that struck its systems on November 2. The exchange said it would cover the losses after suspending deposits and withdrawals, which remain paused with no restart date.

Estimates of the stolen amount vary. Mercado Bitcoin put the value at about $38 million, while blockchain security firm Hypernative identified more than $40 million in suspicious transfers. Arkham traced at least $46 million, and Chainalysis estimated the total at about $49 million.

The exchange said it detected and contained the breach early on November 2 and immediately froze deposits and withdrawals. In a Portuguese-language statement on X, Mercado Bitcoin said: “We identified and quickly contained a security incident in one of our systems early this morning. As a preventive protection measure, deposits and withdrawals are temporarily suspended.”

Mercado Bitcoin also said that no customer had lost money and that no data had leaked. The exchange has not disclosed how the attackers gained access.

The company’s official X post said customer assets remained secure and that balances continued to be recorded in the respective accounts:

Olá. Primeiro, o mais importante: os ativos dos clientes estão garantidos . Os saldos continuam registrados nas respectivas contas. Ontem (2/11), identificamos um incidente de segurança. Acionamos na hora nossos protocolos de segurança e governança e informamos as autoridades.… — Mercado Bitcoin (@MercadoBitcoin) November 3, 2026

The exchange later said the value of the assets involved was about $38 million. “After a quick action with the crypto community and strategic partners, including Tether, Circle, Paxos, BRL1 and Chainalysis, we have already blocked $11 million,” Mercado Bitcoin said in another Portuguese-language update on X.

Hypernative said the suspicious transfers took place across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron. Arkham analysts traced at least $46 million, while Chainalysis put the amount at approximately $49 million and said nearly $10 million had been frozen. Mercado Bitcoin has not clarified whether its $38 million figure includes assets that were frozen.

Tether, the issuer of the USDT stablecoin, which is pegged to the U.S. dollar, froze more than $4.5 million in USDT connected to the incident, CEO Paolo Ardoino said on X. A freeze prevents tokens from moving but does not return them to their owner. Mercado Bitcoin’s stated commitment to cover the losses therefore remains central to the outcome.

The incident came days after hackers drained more than $6 billion from Binance, the world’s largest cryptocurrency exchange, on October 29. The FBI attributed that theft to North Korea’s TraderTraitor group. Mercado Bitcoin has not linked its incident to the Binance attack. Four days separate the two breaches, which together put reported losses above $6 billion at two of the industry’s largest custodians of customer funds.

Binance also said it would absorb the losses rather than pass them on to users. “Binance will absorb the financial impact of the stolen funds, not our users,” CEO Richard Teng wrote on X, adding that about 95% of the affected assets had been replenished.

Neither exchange’s pledge can be independently verified from outside the companies. A guarantee to cover losses depends on the funds available to support it, and exchanges are not required to disclose their internal books to customers.

For now, Mercado Bitcoin’s deposits and withdrawals remain suspended. The exchange said it would publish updates on X and resume services once full security has been restored. The open questions to follow are how attackers gained access, whether more of the stolen funds can be frozen or returned, and whether the exchange’s $38 million estimate will be reconciled with the higher figures from on-chain analysts.

Source: https://decrypt.co/382459/brazil-mercado-bitcoin-will-refund-users-40-million-hack

Official X post: https://x.com/MercadoBitcoin/status/2117637227551273267?a=_VWDCpmll6S0IKPlMos&s=20