Mercado Bitcoin: Security Incident, Platform Paused, US$36.3M Affected

Assets affected equivalent to US$36.3 million "at this moment" and US$12.9 million blocked, per Mercado Bitcoin, 3 Nov (claimed; translated from Portuguese by NullMeridian).

Root cause: Not published. Mercado Bitcoin has not described the attack vector.

Timeline, as sourced: Per Mercado Bitcoin: incident identified 2 Nov 2026 (no time given); platform paused; update 3 Nov 15:17 UTC; 4 Nov update sets a gradual return via website from 9 Nov.

Claimed (Mercado Bitcoin) (3 Nov post (opens in a new tab), translated from Portuguese by NullMeridian): on 2 Nov it identified a security incident, triggered its security and governance protocols, informed the authorities and paused the platform. It says client balances remain recorded in their accounts, assets affected total the equivalent of US$36.3 million at the time of the post, and US$12.9 million had been blocked, with that work continuing.

Claimed (Mercado Bitcoin) (4 Nov post (opens in a new tab), translated): no client will lose assets; MB will restore the affected assets with its own resources. Access returns gradually via website from Monday 9 Nov for balances and statements; transfers, withdrawals and trading follow as each module passes final security validation.

Unknown: attack vector, affected chains and addresses, and who blocked the US$12.9M.