Brazilian cryptocurrency exchange Mercado Bitcoin suspended deposits and withdrawals on Monday, November 2, after investigators identified suspicious transfers from wallets linked to the platform. Blockchain security researchers estimated losses exceeding $40 million, and an analyst at Arkham Intelligence traced more than $46 million in transfers connected to the incident. The halt leaves the platform's customers unable to move funds in or out while the investigation runs.

The company said it identified and quickly contained a security incident in one of its systems in the early hours of Monday. In a statement posted on X, Mercado Bitcoin said customers suffered no losses and that no data had been leaked, describing the suspension of deposits and withdrawals as a precautionary protection measure. The exchange has not confirmed a loss figure or explained how the attacker gained access, and the reported amounts remain estimates from outside analysts rather than confirmed company disclosures.

Comunicado oficial: Identificamos e contivemos com rapidez um incidente de segurança em um de nossos sistemas nesta madrugada. Reforçamos que: • Não houve nenhum prejuízo aos clientes; • Não houve vazamento de dados. Como medida preventiva de proteção, depósitos e saques…

— Mercado Bitcoin (@MercadoBitcoin) November 2, 2026

Mercado Bitcoin Wallets Drained Across Multiple Networks

Security firm Hypernative reported suspicious activity across at least 10 blockchains, including Ethereum, Bitcoin, Solana, Tron, Polygon, Avalanche and Stellar. According to researchers, most of the transfers took place between 06:19 and 06:53 UTC.

The suspected attacker received approximately 2,852 ETH, 106 BTC, 10,700 SOL, 6.7 million XLM and 77,000 AVAX, while the affected wallets also held more than 200 other tokens. Researchers determined that the movements involved ordinary wallet transfers rather than the exploitation of a smart contract flaw. That finding points to direct wallet compromise rather than an on-chain exploit, leaving the central question — how that access was obtained — unanswered by the company.

Arkham Intelligence analyst Emmett Gallic tracked more than $46 million in transfers linked to the breach. The incident followed the record $6.3 billion theft from Binance reported on October 29.

Exchange Says Customers Suffered No Losses

Mercado Bitcoin said it identified and contained the breach early on Monday and kept deposits and withdrawals closed while its investigation continues. The company published wallet addresses across Bitcoin, Solana, Tron, Stellar and Ethereum-based networks, saying its teams were tracing the missing assets and working with authorities. The public listing of the addresses gives outside analysts a way to monitor the funds as they move.

Tether Freezes Funds Linked to the Breach

Tether CEO Paolo Ardoino said the company froze more than $4.5 million in USDT connected to the Mercado incident. The freeze shows the recovery lever stablecoin issuers hold, since frozen USDT cannot be moved by the wallets holding it.

Separately, Binance has begun restoring withdrawal services after its own breach. The exchange said it had covered roughly 95% of the affected assets by Sunday, with its recovery effort including company funds and frozen tokens as investigators continue following the stolen cryptocurrency.

Other Crypto Platforms Face Security Incidents

The FBI attributed the Binance theft to North Korea's TraderTraitor group on October 31, and officials said the hackers were converting assets into ether. No evidence publicly connects that group to the Mercado Bitcoin incident.

The incidents, all disclosed within four days, have drawn security researchers, the FBI and a stablecoin issuer into active responses across the affected platforms.

On October 29, prediction market operator Polymarket reported a separate security breach tied to a third-party service provider. Estimated customer losses reached $2.7 million, and trading briefly stopped.

Mercado Bitcoin has not named a suspect or set a date for reopening deposits and withdrawals. The company said its investigation and efforts to trace the transferred assets remain underway as investigators review the transactions. The unresolved items to watch are a confirmed loss figure, any further freezes or recoveries of the traced funds, and a date for restoring deposits and withdrawals.

Source: CoinCentral