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Mercado Bitcoin halts withdrawals after suspected $40M+ drain

Brazil's largest crypto platform Mercado Bitcoin froze deposits and withdrawals Nov 2 after a security incident; Hypernative flagged $40M+ in suspicious outflows. The firm claims no customer harm.

Published 3 min read
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Mercado Bitcoin, which bills itself as Latin America's largest digital-asset investment platform with about 4.5 million customers, suspended all deposits and withdrawals on Monday, November 2 after what it called a security incident. Blockchain-security firm Hypernative flagged suspicious outflows that may exceed US$40 million across at least ten blockchains. The company has not confirmed any amount, and independent researchers dispute its claim that no customers were harmed.

What the company says

In posts on X, Mercado Bitcoin said it "identified and quickly contained" a problem in one of its systems overnight, suspended deposits and withdrawals as a precaution, and stated there was no harm to customers and no data breach. It gave no timeline for restoring service. The firm said its teams are "investigating the case, tracking the assets, and coordinating measures with the competent authorities." The incident was reported by Recorded Future News and across Brazilian outlets including InvestNews and Money Times.

What the chain shows

The figures come from blockchain-tracking firms, not the company:

  • Hypernative reported suspicious movements that could top US$40 million, spread across wallets on at least ten networks.
  • Recorded Future cited blockchain-security companies putting outflows at more than $46 million late Sunday night.
  • Tether's CEO said the platform froze about $4.5 million, with roughly $2 million more frozen by other platforms.

Those on-chain movements alone do not prove the funds left Mercado Bitcoin's treasury, and the exchange has not published a figure. Several researchers pushed back on the "no customer harm" line, pointing to chain evidence of drained user wallets — a contradiction worth flagging rather than resolving on day one.

Attribution

None. No group has claimed responsibility, and no one has named an actor. The incident lands days after the ~$6.3 billion Binance theft the FBI attributed to North Korea, but nothing ties that activity to Mercado Bitcoin, and we won't imply a link that the evidence doesn't support.

What to do today

  1. If you hold funds on Mercado Bitcoin, assume withdrawals stay frozen until the exchange confirms otherwise; watch its official channels, not resellers or screenshots.
  2. Rotate API keys tied to the platform and revoke any third-party authorizations.
  3. Watch for incident-themed phishing — "verify your wallet," "emergency withdrawal" — which reliably follows exchange outages.
  4. If you run an exchange or custodian, this is the recurring lesson: hot-wallet exposure plus thin withdrawal controls turns a system compromise into an irreversible loss before anyone reads the alert.

Context

This is the second nine-figure crypto incident in a week, after Binance, and fits a longer pattern of custodial platforms losing hot-wallet balances faster than their monitoring can react. The on-chain trail is public — which is why third-party firms, not the exchange, produced the first loss estimates — but attribution and the true customer impact will take days. Treat early numbers as estimates and the "no impact" messaging as a claim, not a finding.

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