Mercado Bitcoin Halts Withdrawals as $40M Flagged Across 10 Chains

Mercado Bitcoin suspended deposits and withdrawals on Monday, 2 November, after a security incident. Blockchain security firm Hypernative flagged more than $40 million in suspicious transfers that may be linked to it, in a preliminary analysis spanning at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron.

The Brazilian exchange says no customer lost money and no customer data leaked, and it described the suspension as a precaution. It has not confirmed Hypernative's figure. It has also not said which system was breached or how the attackers got in.

Tether Freezes 4.5 Million USDT Linked to the Breach

Tether CEO Paolo Ardoino said on X that the company froze more than 4.5 million USDT linked to the incident.

Mercado Bitcoin has published the destination addresses it identified on five networks: EVM chains (blockchains built to run the same code as Ethereum), Bitcoin, Solana, Stellar and Tron. A public list gives other platforms a way to watch where those funds move next.

The freeze adds a second link between the two companies. Tether announced a $20 million investment in Mercado Bitcoin in July, when it said the exchange served 4.5 million users.

Loss Size and Reopening Date Remain Unconfirmed

The $40 million figure is an outside estimate of suspicious transfers, not a confirmed loss. Other analysts have put the total higher, and Mercado Bitcoin has confirmed no number. What the exchange finally loses will also depend on how much is frozen or recovered, which is not yet known.

What is still missing:

• A date for resuming deposits and withdrawals. None has been given.
• How the attackers got in, and which system was hit.
• Any confirmed attribution to a group.

The incident lands five days after attackers drained more than $6 billion from Binance on October 29. Nothing confirmed so far ties the two breaches together.

The next fixed point for Mercado Bitcoin users is the reopening of withdrawals, and whether the exchange puts its own figure on the loss when it does.