Mercado Bitcoin Pledges to Cover Losses From $38M+ Security Breach

Mercado Bitcoin, Brazil's largest cryptocurrency exchange, says it will absorb the losses from a November 2 security breach that drained roughly $38 million by its own count — and possibly as much as $49 million according to blockchain analytics firm Chainalysis.

The exchange detected the intrusion early on November 2 and froze deposits and withdrawals as a preventive measure. "We identified and quickly contained a security incident in one of our systems early this morning," Mercado Bitcoin said in a Portuguese-language statement on X. "As a preventive protection measure, deposits and withdrawals are temporarily suspended." The company says no customer lost funds and no data leaked. It hasn't disclosed how the attackers got in.

How big is the loss?

The figures depend on who's counting. Four separate estimates are in circulation:

• Mercado Bitcoin: about $38 million in assets involved
• Hypernative: more than $40 million in suspicious transfers across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron
• Arkham: at least $46 million traced on-chain
• Chainalysis: about $49 million, with nearly $10 million frozen

The exchange hasn't said whether its $38 million figure includes assets already frozen. That gap matters: it's the difference between a contained incident and a materially larger shortfall.

What's been recovered so far?

Roughly $11 million has been blocked, according to a follow-up Mercado Bitcoin posted on X. "After a quick action with the crypto community and strategic partners, including Tether, Circle, Paxos, BRL1 and Chainalysis, we have already blocked $11 million," the exchange said.

Tether, issuer of the USDT dollar-pegged stablecoin, froze more than $4.5 million in USDT tied to the incident, CEO Paolo Ardoino said on X. Circle, Paxos and Brazilian stablecoin BRL1 are also involved in the containment effort.

A freeze stops tokens from moving — it doesn't return them. That's why the exchange's pledge to cover customer losses carries the real weight here, and Mercado Bitcoin has been direct about it: "Primeiro, o mais importante: os ativos dos clientes estão garantidos" — first, the most important thing: customer assets are guaranteed, and balances remain registered in their accounts.

Is this connected to the Binance hack?

Mercado Bitcoin hasn't linked its breach to the October 29 attack on Binance, in which hackers drained more than $6 billion and the FBI attributed the theft to North Korea's TraderTraitor group. The timing, days apart, has drawn attention regardless.

Binance made the same promise Mercado Bitcoin now has. "Binance will absorb the financial impact of the stolen funds, not our users," CEO Richard Teng wrote on X, noting that about 95% of affected assets had been replenished.

Neither guarantee is externally verifiable. A loss-coverage pledge is only as good as the capital behind it, and exchanges aren't required to show customers their books.

What happens next?

Deposits and withdrawals remain suspended with no restart date. Mercado Bitcoin says it will publish updates on X and resume services once full security is restored. For a platform of its size in Brazil's market, the recovery timeline — and whether frozen funds translate into returned funds — is now the operative question.