Mercado Bitcoin, Brazil’s largest cryptocurrency exchange, has pledged to absorb financial losses resulting from a security breach detected on November 2. The company stated that customer assets are guaranteed and balances remain recorded in respective accounts, emphasizing that users will not bear the cost of the incident. Upon identifying the breach, the exchange immediately froze all deposits and withdrawals as a preventive measure, though it has not yet provided a timeline for resuming services.
Discrepancies exist regarding the total value of stolen assets. While Mercado Bitcoin reported approximately $38 million involved, independent blockchain analytics firms provided higher estimates. Security firm Hypernative flagged over $40 million in suspicious transfers across multiple blockchains, including Bitcoin, Ethereum, Solana, and Tron. Arkham traced at least $46 million, and Chainalysis estimated roughly $49 million, noting that nearly $10 million had been frozen. The exchange acknowledged blocking $11 million through collaboration with partners such as Tether, Circle, Paxos, and Chainalysis.
Tether CEO Paolo Ardoino confirmed that more than $4.5 million in USDT tied to the incident was frozen. However, freezing tokens prevents movement but does not automatically return funds to owners, placing significant weight on the exchange’s promise to cover losses. This incident follows a separate $6 billion theft from Binance on October 29, which the FBI attributed to North Korea’s TraderTraitor group; however, Mercado Bitcoin has not linked its own breach to that attack. The exchange continues to investigate how attackers accessed its systems and has not disclosed specific details on the method of intrusion.
Mercado Bitcoin’s commitment to indemnify users reflects a growing industry standard where exchanges prioritize reputational stability over immediate liability disputes following breaches. By explicitly stating that customer balances are guaranteed, the platform aims to prevent panic-driven capital flight, which could exacerbate liquidity issues during the suspension period. This approach mirrors recent actions by major global players like Binance, suggesting a consolidated response strategy among top-tier exchanges to maintain user trust despite operational failures.
However, the variance in loss estimates between the exchange and third-party analysts highlights ongoing transparency challenges in post-hack assessments. The discrepancy suggests either differing methodologies in tracking cross-chain movements or potential underreporting by the entity itself. For regulators and institutional investors, the lack of clarity on the attack vector and the indefinite service suspension pose significant operational risks. Monitoring whether the exchange can successfully recover the blocked funds versus absorbing the full loss will be critical in assessing its long-term solvency and compliance posture.
