Mercado Bitcoin hack prompts pause after multi-chain drain
Brazil's Mercado Bitcoin paused deposits and withdrawals on November 2 after a Mercado Bitcoin hack drained wallets across many chains, with security firms putting losses near $40 million to $49 million.
The second large exchange breach in a week has hit Latin America. A Mercado Bitcoin hack emptied hot wallets across multiple blockchains on November 2, prompting Brazil's largest crypto platform to pause deposits and withdrawals while investigators traced an estimated $40 million to $49 million in outflows.
What happened
CoinDesk reported that Mercado Bitcoin suspended deposits and withdrawals after wallets on at least 10 blockchains were drained, with security firms estimating losses of $40 million or more. The exchange said it had contained the incident, that customers were not financially harmed and that no customer data was breached. How the attacker obtained signing access remains unknown, and there is no public evidence tying the drain to the Binance theft days earlier.
Opsek figures cited by CoinDesk put the attacker's haul at roughly 2,852 ETH, 106 BTC, 10,700 SOL, 6.7 million XLM and 77,000 AVAX, plus more than 200 other tokens, moved as plain signed transfers rather than a smart-contract exploit. Biggest outflows clustered between about 06:19 and 06:53 UTC across Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Chain, Stellar and other networks.
Other tallies run higher. Cointelegraph framed the theft near $46 million and said addresses linked to the incident kept receiving funds for hours after the pause. Chainalysis put stolen funds at about $49 million across 17 chains and said it helped freeze nearly $10 million with partners. Bitquery counted $48.5 million leaving wallets on 10 chains and said 35,853 Ethereum deposit addresses were emptied, with Tether and Paxos freezing $7.3 million; CoinDesk separately noted Tether founder Paolo Ardoino confirming $4.5 million of USDT frozen.
Why it matters
Coming days after Binance's multi-billion-dollar hot-wallet loss, the episode underlines how quickly signing-key compromise can empty exchange wallets even when operators claim containment. Our coverage of the Binance withdrawals restart showed how long recovery and freezes can take; Mercado Bitcoin is still early in that sequence.
Stablecoin freezes are again the first line of defense. The gap between Ardoino's $4.5 million USDT figure and Bitquery's $7.3 million Tether-plus-Paxos total shows how incomplete early tallies can be while coins keep moving. Chainalysis's nearly $10 million freeze claim, if sustained, would still leave most of the estimated haul outside issuer control.
Latin American exchange risk is also in focus. Cointelegraph noted Mercado Bitcoin's 4.5 million users as of July and recalled that Chile's Tether-backed Orionx closed after a forensic audit found more than $7 million of customer assets outside its control. Users will watch whether the firm truly absorbs losses as promised after the Mercado Bitcoin hack.
Attribution remains open. Unlike last week's TraderTraitor attribution for Binance, no group has been publicly blamed for the Brazilian drain.
What's next
Watch whether deposits and withdrawals reopen, whether more stablecoin freezes land, and whether Brazilian data-protection rules force further disclosures. Chainalysis's response note details its freeze coordination.
Investigators are still tracing coins that Cointelegraph said remained in associated addresses, including all 106 BTC, after the Mercado Bitcoin hack.
A prolonged pause would also test proof-of-reserves messaging across the region's exchanges.
This article is for information only and is not investment advice.