Brazilian cryptocurrency exchange Mercado Bitcoin has pledged to cover customer losses following a major security incident on Nov. 2, 2026, that involved approximately $38 million in digital assets. The attack presents a substantial financial and operational challenge for one of Latin America’s largest cryptocurrency platforms, drawing attention from customers, blockchain investigators, and the broader digital asset industry.
Company Guarantees No Customer Losses
In an update to users, the exchange stated: “Mercado Bitcoin assures you that you will not suffer any loss of assets due to the security incident we identified today on our platform.” The commitment effectively means the business will make affected users whole, regardless of how much cryptocurrency investigators ultimately recover.
Emergency Shutdown and Investigation
Mercado Bitcoin detected the suspicious activity in the early hours of Monday and subsequently suspended deposits, withdrawals, and access to platform services as a preventive measure. The company activated its internal security procedures and notified the relevant authorities. It also warned users to rely on official communications rather than unsolicited messages or purported support representatives.
Preliminary analyses suggest attackers obtained control of credentials capable of authorizing transactions, potentially exposing both hot wallets and customer deposit addresses. According to a Bitquery analysis, suspicious activity reportedly spanned chains including Ethereum, Bitcoin, Solana, Stellar, Arbitrum, Tron, and Polygon, with some investigators describing unauthorized movements continuing beyond the initial wave of transfers. Unlike a smart-contract exploit, this suspected compromise concerns access to the mechanisms used to approve legitimate blockchain transactions. The precise entry point has not been conclusively established.
Partners Block $11 Million
Mercado Bitcoin enlisted several cryptocurrency companies to restrict assets associated with the breach. “In a swift action with the crypto community and strategic partners—including Tether, Circle, Paxos, BRL1, and Chainalysis—we have already blocked US$ 11 million,” the exchange stated. Other amounts eligible for blocking have been identified, according to the company, though it has not provided a definitive figure for additional recoverable assets.
Certain centrally issued stablecoins contain administrative functions that permit authorized issuers to prevent token transfers, while native BTC has no comparable issuer-controlled freezing mechanism. Importantly, restricting stolen tokens does not automatically return them to their previous owners; subsequent recovery may require cooperation from custodians, legal authorities, or other parties controlling the affected assets.
Discrepancy in Loss Estimates
Bitcoin.com News previously reported that Arkham Intelligence analyst Emmett Gallic estimated more than $46 million in suspicious transfers on Monday, exceeding Mercado Bitcoin’s official accounting by at least $8 million. The competing figures have not been publicly reconciled, and it remains unclear whether both assessments encompass identical transactions or asset categories.
A Defining Test for a Brazilian Crypto Heavyweight
Founded in 2013, Mercado Bitcoin expanded from a bitcoin brokerage into a diversified financial technology business offering spot trading, staking, tokenized private credit, and payment services. The São Paulo-based company serves approximately 4.5 million to 4.8 million customers and has reported cumulative transaction volume exceeding 215 billion Brazilian reais. Its expansion attracted a $200 million Softbank investment in 2021, valuing the business at approximately $2.1 billion and establishing it as a Brazilian cryptocurrency unicorn.
The exchange has not provided a definitive reopening date. “The resumption of services will take place as soon as full security conditions are in place, and deadlines will be communicated exclusively through our official channels,” the company emphasized. The remaining challenge is whether Mercado Bitcoin can demonstrate that its security controls have been repaired sufficiently to prevent another intrusion. Financial compensation can address missing balances, but restoring confidence in the systems protecting those balances requires a different kind of proof.
