Mercado Bitcoin pauses transfers as monitors flag $40M drain

Mercado Bitcoin users cannot deposit or withdraw through the exchange while it investigates a security incident reported on Monday, November 2. Blockchain security firms flagged more than $40 million in transfers from wallets across at least 10 chains, though the exchange has not confirmed a loss figure.

For customers, the immediate effect is a pause on moving funds through the platform, with no restart date yet reported.

According to CoinDesk’s report, the outflows included Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Smart Chain and Stellar. Security firm Hypernative estimated the transfers at more than $40 million. Mercado Bitcoin said it identified and contained an incident in one of its systems, but did not say how access was obtained.

What can Mercado Bitcoin customers do while transfers are paused?

Deposits and withdrawals are temporarily suspended, so customers cannot move assets into or out of their accounts through those functions. The exchange described the suspension as a preventive measure while it investigates, tracks assets and coordinates with authorities. Decrypt reported on November 2 that the exchange had not given a date for resuming service.

Mercado Bitcoin said no customers suffered losses and no data was leaked. Those are the exchange’s statements; the company has not published a detailed account of the incident or explained how it will handle the assets that moved. It also has not publicly confirmed Hypernative’s estimate of the amount involved.

How much was moved, and what has been recovered?

In Decrypt’s report, Hypernative’s preliminary analysis put suspicious transfers above $40 million across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron. Decrypt also reported that Tether CEO Paolo Ardoino said Tether froze more than 4.5 million USDT linked to the incident. That freeze restricts movement of those tokens; it does not by itself return them to Mercado Bitcoin.

The reported transactions were not described as a smart-contract exploit: CoinDesk said the transfers were plain transactions, while how the attacker gained signing access remains unknown. Mercado Bitcoin later published destination addresses on several networks to help track the funds. The exchange has not said when deposits and withdrawals will resume, so customers should check its official updates before trying to move funds.

Source material

• CoinDesk’s report — coindesk.com
• Decrypt’s report — decrypt.co