Mercado Bitcoin halts withdrawals after more than $40M is drained from its wallets

Brazilian crypto exchange Mercado Bitcoin suspended deposits and withdrawals on 2 November after wallets tied to the platform were drained across at least 10 blockchains. Security firms estimate losses above $40 million. The largest outflows ran between 06:19 and 06:53 UTC, with most funds moving to fresh addresses.

The exchange said on X that it had identified and contained a security incident. It reported no harm to customers and no data breach, and said deposits and withdrawals are paused as a precaution while it works with authorities. The transfers were plain transactions rather than a smart contract exploit, and how the attacker obtained signing access is unknown.

Tether founder Paolo Ardoino said $4.5 million of USDT linked to the hack has been frozen. No one has been blamed, and there is no public evidence linking it to the Binance hack.