Mercado Bitcoin Hack: Brazil’s Top Exchange Freezes $11 Million

Mercado Bitcoin, Brazil’s largest cryptocurrency exchange, has taken its platform offline and suspended all deposits and withdrawals after hackers drained its hot wallets early on Monday, November 2. In its latest update, the company says it has frozen about $11 million of the stolen crypto and promises that no customer will lose assets because of the Mercado Bitcoin hack.

The exchange first described the attack as a “security incident in one of our systems” that it “quickly contained,” adding that there was no data leak. Blockchain security firms put the outflow higher: Hypernative flagged more than $40 million in suspicious transfers across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron, according to Decrypt.

What We Know About the Mercado Bitcoin Hack

In a Portuguese-language update published Monday night, Mercado Bitcoin said only its hot wallets were hit. These are the online wallets the exchange uses for daily deposits and withdrawals, while most customer assets sit in offline cold storage.

With help from Tether, Circle, Paxos, BRL1 and Chainalysis, the company says it has blocked around $11 million so far. About $38 million is still not frozen, and the exchange says it has identified more funds that could be blocked. Tether CEO Paolo Ardoino separately said the stablecoin issuer froze more than 4.5 million USDT tied to the attack.

Mercado Bitcoin also published the destination addresses it traced on five networks (EVM chains, Bitcoin, Solana, Stellar and Tron) so other platforms can track the funds. It has not said how the attackers got in, and it has not given a date for reopening. The company says the platform will return only once operations are confirmed to be safe.

Experts Question the “No Customer Losses” Claim

Some blockchain researchers have pushed back on the exchange’s early statements. As The Record reports, several analysts shared on-chain evidence that the attackers also moved funds from some customer wallets, and blockchain security companies estimated that more than $46 million left the platform late on Sunday night.

Mercado Bitcoin calls itself Latin America’s largest digital asset investment platform, with about 4.5 million customers. Its pledge to cover the losses mirrors the response at Binance, which reopened withdrawals after its own record hack just days earlier. That $6.3 billion theft was blamed by the FBI and the US Secret Service on North Korean hackers.

The wider industry is under pressure too. Last week, Chainalysis disclosed a data breach in which attackers used AI-backed tools to reach internal systems.

What Mercado Bitcoin Customers Should Do Now

For now, users cannot move funds in or out of the exchange. Mercado Bitcoin warns that it never asks for passwords, verification codes or recovery phrases, and that it does not offer refunds through links, WhatsApp or phone calls. Any such message is a scam, so customers should only trust updates on the official app, website, Instagram and X accounts.

The incident is another reminder of why long-term holdings are safer off exchanges. Our guide on what a cold wallet is and how to use one explains the basics of self-custody.