Mercado Bitcoin Puts Incident at $38 Million, Freezes $11 Million

Mercado Bitcoin now puts its security incident at about $38 million, with $11 million frozen, per an update on X posted at 6:17 p.m. ET Monday.

In the same thread, the Brazilian exchange told clients in Portuguese that they "will not suffer any loss of assets" from the incident. It did not say where the money to cover the gap would come from.

Who helped Mercado Bitcoin freeze funds

Mercado Bitcoin said it blocked the $11 million with partners including Tether, Circle, Paxos, BRL1 and Chainalysis. It said other amounts that can be blocked have been identified and that containment is continuing, Unchained reported.

How can stolen crypto be frozen at all? Stablecoins such as Tether's USDT and Circle's USDC are run by companies that can block tokens sitting at a given address. Once a coin is blocked, it cannot be moved or spent. Native coins like bitcoin and ether have no such switch, which is why analytics firms like Chainalysis track them instead.

The numbers so far

The $38 million figure is the first loss estimate from the exchange itself. Earlier on Monday, blockchain security firm Hypernative had estimated outflows of more than $40 million. That leaves about $27 million not yet frozen, based on the exchange's own figures.

Deposits and withdrawals stay suspended. Replying to a customer on X, Mercado Bitcoin said it has no exact date yet and will share the timing only through official channels.

The exchange still has not said how the incident happened. It came four days after Binance's Oct. 29 hot-wallet drain. No one has tied the two events together.

In our opinion: A firm promise that clients lose nothing is the most important sentence an exchange can publish after a breach, and now it has to be backed by a reopening with balances intact. Freezing almost a third of the money within a day is what fast help from stablecoin issuers looks like. The next things to watch are a restart date and a plain account of how the funds left.