Brazil's largest crypto exchange Mercado Bitcoin has halted deposits and withdrawals. This happened on Monday, November 2, after the exchange's wallets were emptied across ten blockchains at once. Specialist security firms estimate losses above $40 million.
An exchange wallet is an address on a blockchain where the platform holds client funds. While operations are closed, no one can deposit or withdraw funds.
For a trader, this is a risk of the platform itself. The balance on the account is visible, but there is no access to the money.
What left the wallets?
The main transfers took place in a narrow window - from 09:19 to 09:53 Moscow time. Funds were sent to new addresses from wallets on the Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BSC and Stellar networks.
According to the report cited by Pablo Sabbatella, founder of the security company Opsek, the attacker now holds:
- 2,852 ETH and 106 BTC
- 10,700 SOL
- 6.7 million XLM
- 77,000 AVAX
- more than 200 other tokens
Was this not a code hack?
The transfers were ordinary transactions, not a smart contract exploit. That is, the attacker gained access to wallet signing. How exactly he obtained it is not yet known.
The exchange spoke out on X. Here is what it reported:
- "Identified and quickly contained" - that is how the platform described the incident.
- No clients were affected, and there was no data leak either.
- Deposits and withdrawals remain closed as a precaution while the investigation and work with law enforcement are ongoing.
- The recipient addresses have been published on the EVM, Bitcoin, Solana, Stellar and Tron networks so that other market participants can track the funds.
How much money has been frozen?
- $4.5 million in USDT. The block was confirmed by Paolo Ardoino, founder of Tether. USDT is a stablecoin with an exchange rate pegged to the dollar; the issuer can blacklist addresses.
- Confirmation on-chain. Records on Ethereum and Tron show the block on the wallets specified by the exchange.
What does this mean for a trader?
The event came just days after the Binance hack. According to the FBI, the North Korean group TraderTraitor withdrew more than $6 billion from there - the largest theft in crypto history.
There is no public evidence linking the two cases. No culprits have yet been named in the Brazilian incident.
Key point: operations are closed for all clients, although the exchange found no affected clients. We break down how access to capital works without storing coins on an exchange in the academy, and the terms of platforms are collected in the prop firm catalog.
Are your coins sitting on an exchange right now?
Two weeks - two cases. In both, withdrawals are closed, and you are looking at a balance you cannot touch. You calculate market risk, but the risk of the platform itself - you don't, it just happens. Prop trading works differently: you trade not your own coins on an exchange, but the company's account under its rules, and it maintains the infrastructure. In exchange, there are rules and a paid selection process, and this is worth understanding before the next such halt.