SÃO PAULO, November 8, 2026 — Brazil’s largest crypto exchange, Mercado Bitcoin, froze all deposits and withdrawals for seven days after a cybersecurity incident on November 2, 2026, revealing critical gaps in regional exchange resilience and customer trust.
By the Numbers: The Scale of the Breach
The bottom line for investors is a $48.6 million theft. Blockchain analysis by Bitquery traced the stolen assets across 11 blockchains, including the Stellar network. The figure that matters is the timeline: hackers drained 36,042 Ethereum customer deposit addresses for nearly four hours after the exchange publicly claimed it had contained the incident at 9:56 a.m. Brazil time on November 2. This data contradicts the exchange’s initial assurances that customer funds were not accessed.
Mercado Bitcoin serves approximately 4.5 million customers as Latin America’s largest digital assets platform. The attack’s impact was not confined to Brazil; U.S. Google searches for ‘Mercado Bitcoin’ surged 250% during the week-long freeze, signaling international concern. In response, Tether froze $4.5 million USDT and Circle froze additional funds, with over $15 million total frozen across platforms. The exchange itself pledged to cover all user losses from the hack.
A Week of Silence and Phased Reopening
Mercado Bitcoin halted all deposits and withdrawals on November 2, 2026, after the cybersecurity incident. The exchange did not confirm total loss figures or specify which system was breached during the suspension. This week-long freeze left customers unable to access their assets, a period marked by communication failures and uncertainty.
The exchange announced a phased reopening beginning November 9, 2026. In a video shared on X, Vice President Fabricio Tota explained the initial phase would allow customers to view their balances and assets, but not trade or withdraw them. Trading and withdrawals remain delayed pending the completion of independent security assessments. The exchange shared destination addresses for the stolen funds, including those on the Stellar network, for identification and tracking purposes.
Blockchain Evidence vs. Exchange Statements
Blockchain experts disputed the exchange’s claim that customer funds were not accessed. The evidence shows the attacker was able to siphon funds from customer wallets, likely by accessing the private keys or a system capable of signing transactions on their behalf. This method suggests the attacker compromised the core infrastructure managing customer deposits, not just a peripheral system.
The investigation also uncovered a connection to a previous breach. The attack shared wallet connections with a BitMart exchange breach, indicating a possible link between the two incidents. This pattern of reuse by attackers is a key data point for understanding the threat landscape.
Regulatory Implications for Latin America
The incident highlights the difficulty regulators face when overseeing financial activity on decentralized networks. The attack is part of a larger wave of recent crypto crime, including the $6.3 billion hack into the Binance exchange the previous week, now believed to be the largest financial theft in history. This backdrop underscores the urgent need for clear regulatory frameworks in Latin America.
For users, the situation raises a fundamental question: what you actually own on an exchange may not be what you think. The history of collapses like FTX, Celsius, and Mt. Gox shows this risk is not theoretical. Mercado Bitcoin’s week-long freeze and the conflicting information released during that period have eroded trust, making solvency verification a top priority for users in the region. The exchange has not provided a timetable for when full functionality will be restored.
Sources
- Mercado Bitcoin Is Reopening After a Cyberattack Froze Withdrawals for a Week. What Happens to Your Crypto When an Exchange Goes Dark?
- Stellar (payment network)
- Largest crypto exchange in Brazil confirms cyberattack as millions flow out of platform
- Mercado Bitcoin Said Its Hack Was Contained, But Blockchain Data Tells a Different Story
- Mercado Bitcoin Hack $8 Million Larger Than First Reported | PYMNTS.com
- Mercado Bitcoin Halts Withdrawals After $40 Million+ Hack
Photo: Ewan Kennedy / Unsplash (Unsplash License)
