Brazilian cryptocurrency exchange Mercado Bitcoin has pledged to cover losses from a security breach that resulted in approximately $38 million in missing crypto assets. The incident affected wallets across multiple blockchain networks and forced the exchange to temporarily suspend deposits and withdrawals.
The company said customers would not suffer financial losses, while blockchain investigators and industry partners helped freeze approximately $11 million of the affected assets.
The breach was detected on November 2, 2026. Mercado Bitcoin initially described it as a security incident involving one of its systems, saying it had contained the problem and was coordinating with authorities.
Mercado Bitcoin Says Customers Will Not Lose Funds
In an update reported by CoinDesk on November 3, Mercado Bitcoin said the incident resulted in losses estimated at between $38 million and $40 million.
The exchange pledged to cover the shortfall, maintaining that customers would not bear the financial impact. It also said no customer data had been leaked.
Deposits and withdrawals were temporarily suspended as the company investigated the incident, traced the affected assets and worked to restore services safely.
The exchange has not publicly identified the method used to gain access to the affected wallets. It also has not attributed the attack to a specific individual or hacking group.
The distinction matters because the full technical cause remains unknown. Although the incident involved unauthorised crypto transfers, there is not yet enough public information to establish whether the attacker exploited a wallet-management system, compromised signing credentials or used another access route.
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Attack Affected Wallets Across Multiple Blockchains
Blockchain security researchers reported suspicious transfers across at least 10 blockchain networks, with Chainalysis describing activity across 17 networks.
The affected assets included Bitcoin, Ethereum and tokens on networks such as Solana, Tron, Polygon and Base.
Chainalysis said the incident involved approximately $49 million in stolen funds based on its initial analysis. Its investigators worked with Mercado Bitcoin, law enforcement and other industry participants to trace the transactions and identify assets that could be frozen.
The different estimates reflect separate reporting and tracking methods. Mercado Bitcoin’s reported loss estimate was approximately $38 million, while Chainalysis initially tracked a larger amount in suspicious transfers. These figures should not be treated as identical measurements.
The attacker moved assets through multiple wallets, making it necessary for investigators to follow transactions across several networks.
Tether, Circle and Chainalysis Help Freeze Stolen Assets
The response also highlighted the role of centralised stablecoin issuers in crypto investigations.
According to Chainalysis, its investigators coordinated with companies including Tether, Circle, Paxos and other industry participants to identify assets that could be frozen.
Chainalysis said its work helped freeze nearly $10 million in stolen funds. CoinDesk subsequently reported that approximately $11 million had been frozen with assistance from Tether, Circle and Chainalysis.
Tether separately confirmed that it had frozen more than $4.5 million in USDT connected to the incident.
The ability to freeze certain stablecoins is an important distinction in cryptocurrency theft investigations. Unlike Bitcoin, centrally issued stablecoins can include administrative controls that allow issuers to restrict tokens associated with identified addresses.
However, freezing funds does not automatically mean the assets have been returned to the exchange. Recovery and the final financial accounting remain separate steps.
Another Security Test for Centralised Crypto Exchanges
The Mercado Bitcoin incident comes amid renewed scrutiny of exchange security following a separate, much larger breach involving Binance.
The two incidents should not be treated as connected. There is currently no public evidence establishing a link between the attacks.
Nevertheless, the Mercado Bitcoin case raises familiar questions about how exchanges secure wallet infrastructure, manage transaction-signing access and respond when suspicious transfers are detected.
It also demonstrates the limits of relying on withdrawal suspensions alone. Halting deposits and withdrawals can restrict normal platform activity while an investigation takes place, but investigators must also identify compromised systems and prevent further unauthorised transfers.
For customers, the exchange’s pledge to cover losses is significant. The next important developments will be the restoration of normal services, confirmation of the final amount affected and disclosure of how the attacker gained access.
For now, Mercado Bitcoin says customers will not bear the losses. The investigation and asset recovery effort will determine how much of the stolen cryptocurrency can ultimately be recovered.