Mercado Bitcoin Pledges Coverage After $40 Million Hack
The Brazilian exchange halted withdrawals after unauthorized transfers across 10 blockchains prompted emergency asset-freezing efforts.
- By Jesse Jacobs
- Nov 04, 2026
Brazilian digital asset exchange Mercado Bitcoin suspended account operations and pledged to absorb up to $40 million in platform losses following a multi-chain security breach, according to a reporting by CoinDesk.
Unauthorized outflows emptied hot wallets across at least 10 networks, including Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Chain and Stellar. Blockchain investigators noted the activity consisted of standard, signed transactions rather than an exploit of smart contract code, indicating the attacker gained signing access to the exchange’s operational wallets, the outlet stated.
Mercado Bitcoin said it contained the incident shortly after detection, confirming user balances remain intact and no customer data was exposed during the breach, according to the report. Platform administrators temporarily paused deposits and withdrawals while forensic teams began tracing transaction destinations alongside law enforcement agencies.
The exchange later confirmed roughly $38 million was removed, while external partners helped freeze approximately $11 million of the stolen assets, CoinDesk added in a separate report. The coordinated intervention involved stablecoin issuers Tether and Circle, blockchain intelligence firm Chainalysis and other infrastructure providers that blacklisted flagged recipient addresses.
The platform published destination wallet addresses across multiple networks to aid third-party investigators in tracking the remaining assets as security teams work toward restoring normal platform operations.