Mercado Bitcoin, Brazil's largest cryptocurrency exchange, said it identified and contained a security incident in one of its systems early on Monday, Nov. 2. As a precaution it suspended deposits and withdrawals, and it published the destination wallet addresses so security firms and other platforms can trace the funds. The breach came less than four days after the record theft from Binance, sharpening concern about the safety of centralized exchanges.
How big the loss is and how the attacker is moving
The numbers differ by source. The exchange says about $38 million was lost, while security researchers initially pointed to more than $40 million. Arkham Intelligence data shows wallets tied to the attacker holding about $46 million, including roughly $8.4 million in Ether, $8.2 million in Bitcoin and $1.8 million in PEPE; the rest has not been itemized.
The funds were drained from hot wallets across at least 10 blockchains. An Arkham analyst said the attacker was sweeping money from older deposit addresses and selling memecoins and other altcoins. The addresses the exchange published span Bitcoin, Ethereum-compatible networks, Solana, Stellar and Tron.
The exchange's response and the freezing effort
Mercado Bitcoin says customers suffered no financial loss and that no personal data was exposed. It pledged to cover the stolen amount itself, and said its teams are investigating, tracing assets and coordinating with authorities. Its status page showed a partial outage, and no reopening date has been given.
On recovery, Tether CEO Paolo Ardoino confirmed the company blocked more than 4.5 million USDT linked to the incident. With Tether, Circle and Chainalysis involved, the total of immobilized assets has since been reported at roughly $9 million to $11 million, spread across assets such as USDC, PAXG and RLUSD. Tether had announced a $20 million investment in Mercado Bitcoin in July.
Context: a run of security incidents
This is the second major exchange incident in under a week. The Oct. 29 theft from Binance was put at about $6.3 billion, and the FBI attributed it to North Korea's TraderTraitor group. Investigators have not linked that group to the Mercado Bitcoin breach. Earlier this year, Bitget lost about $388 million in September, and Bybit lost about $1.5 billion in February 2025.
The loss here is far smaller than those cases, and the exchange has promised compensation. Still, the fact that the attacker is moving and selling assets shows that sell pressure from stolen funds is real, especially in thinly traded tokens.
What it means for traders
For futures traders, the incident is unlikely to move Bitcoin or Ethereum on its own, because the sum taken is small relative to market size. Bitcoin traded around and below $77,000 on Nov. 3 as pressure from tech stocks and nerves before the U.S. midterm vote weighed on markets; those factors matter far more than this hack.
The more relevant issue is counterparty risk: collateral held on any exchange carries that venue's operational and security risk, and a pause in deposits and withdrawals can interrupt margin transfers between platforms. The attacker's sales of memecoins and altcoins can cause local slippage in low-liquidity pairs, so volume and order-book depth deserve a check before placing large orders.
Worth watching next: when the exchange reopens deposits and withdrawals, progress on freezing and recovering funds, and whether any other venue discloses an incident. You can compare venues on the exchange ranking and size positions with the position calculator.