Blockchain security firm Hypernative estimated that over $40 million in unauthorized transfers occurred across at least 10 blockchains linked to Mercado Bitcoin's wallets

From the articleBrazil’s Largest Crypto Exchange Mercado Bitcoin Hit by Possible $40M HackAlso in Brazil's Largest Exchange Mercado Bitcoin Halts Withdrawals After $40 Million Hack - Decrypt, Mercado bitcoin hit by $40 million hack across 10 blockchains