Brazilian cryptocurrency exchange Mercado Bitcoin will begin restoring customer account access on Monday, roughly a week after attackers drained more than $46 million in digital assets from its systems, the company said. The first phase is deliberately narrow: customers can log in through the exchange's website to review balances, statements, holdings and investments, but cannot move money.
Transfers, withdrawals and trading will return only in later stages, each gated by independent security testing, according to the company. Mercado Bitcoin framed the sequencing as a precaution, saying it wants users back on a safe baseline before re-enabling any function that could expose them to further risk.
The breach, disclosed earlier in the week, involved attackers moving funds out of the exchange's hot wallets and customer deposit addresses using ordinary transfers rather than exploiting a smart contract. Blockchain analytics firms put the loss at more than $46 million.
Mercado Bitcoin has pledged to make affected customers whole from its own balance sheet. It said more than $15 million of the stolen assets have already been frozen with help from industry partners, including stablecoin issuers Tether, Circle and Paxos, the BRL1 token project, and blockchain forensics firm Chainalysis.
"Assets impacted by the attack will be covered by company funds, and more than $15 million has been frozen with sector support," the exchange said.
Its proprietary trading desk is preparing buybacks in both Brazilian and international markets to replenish balances left short by the theft, the company said. "Our trading desk is preparing to begin the necessary repurchases in domestic and international markets."
Note: The stolen-asset figure is an estimate by blockchain analytics firms; the frozen total reflects funds secured as of the company's latest update.
On liquidity, the exchange pointed to a strong cash position reinforced by a $20 million investment from Tether, the issuer of USDT, aimed at supporting operational expansion. Mercado Bitcoin did not present that capital as direct hack reimbursement, but said it underpins the company's ability to keep running and fund replenishment during the incident response.
The exchange also published the destination addresses tied to the illicit transfers across Ethereum-compatible networks, Bitcoin, Solana, Stellar and Tron, giving investigators and counterparties a way to trace the money on public ledgers. Arkham Intelligence has grouped 64 addresses it links to the incident under the label "Mercado Bitcoin Hacker," with holdings valued at roughly $45 million at one point this week, though that tally may use different valuation methods and timing than the company's own figures.
Some stablecoins carry issuer controls that let a token's creator block transfers from specific addresses, a mechanism that can help freeze stolen funds quickly when flows are identified. Mercado Bitcoin has not detailed how the $15 million was immobilized, and the freeze does not mean recovery or restitution is complete.
Founded in 2013, Mercado Bitcoin is among Latin America's largest digital asset platforms, serving millions of users. The incident lands as Brazilian investors remain active in crypto despite a global regulatory squeeze, and it puts custody controls at one of the region's flagship venues under scrutiny.
The gap between the $46 million loss estimate and the $15 million secured so far will shape how much the exchange must spend on open-market repurchases to square customer balances. For traders, the shift from read-only access to live withdrawals and order flow is the milestone that matters: it is where the integrity of custody and settlement systems becomes visible in practice. The company said it will keep customers updated as more funds are recovered and additional functions come back online, without giving a firm date for full restoration.
