Mercado Bitcoin Sustains Over $40 Million Crypto Loss This Week

Exchanges and DeFi protocols across multiple blockchains reported significant security compromises between November 1 and November 5, 2026. While Binance reported record losses on October 29, several other high-profile incidents highlight vulnerabilities in both centralized exchanges and decentralized finance infrastructure.

Key Updates This Week

• Mercado Bitcoin reported over $40 million was transferred from exchange wallets following a security breach on November 2, 2026.
• DefiLlama reported 2026 losses reached $8.776 billion across 333 incidents as of November 8, 2026.
• The BTCPay Server vulnerability, exploited in 682 separate sweeps on November 1, was patched in version 2.4.2 in August.

Major Exchange Breaches

Mercado Bitcoin, Brazil's largest cryptocurrency exchange, paused its deposit and withdrawal services after attackers compromised a system on November 2, 2026. More than $40 million in crypto was transferred from exchange-associated wallets across various blockchains during the incident. Tether froze over $4.5 million of the stolen USDT following the breach.

Alongside this incident, BitMart reported a breach on the same day, November 2, 2026. Attackers successfully transferred approximately $391,000 from wallets on three blockchains: Base, Arbitrum, and Optimism. Blockchain investigators traced portions of these stolen funds to addresses associated with the concurrent Mercado Bitcoin exploit.