Brazil’s Mercado Bitcoin Halts Withdrawals After About $46 Million Drained, Days After Binance’s Record Hack

Crypto
Written by Methodical Millions
Illustration of a glowing octagonal vault door ajar with streams of green digital tokens flowing out across a dark navy network, some frozen in ice blocks

Brazil's largest crypto exchange froze deposits and withdrawals on Monday after wallets on at least 10 blockchains were drained. It's the second exchange breach in a week, and a fresh reminder of what "not your keys" really means.

By Methodical Jon | November 2, 2026

Mercado Bitcoin, Brazil's largest cryptocurrency exchange, suspended all deposits and withdrawals on Monday, November 2nd 2026, after what it called a security incident in one of its systems early that morning. Blockchain analytics firm Arkham says wallets tied to the attacker hold about $46 million USD in crypto, according to The Block and CoinMarketCap. The exchange says customers lost nothing and no data leaked. It hasn't said when trading accounts will be able to move money again.

What happened

Security firm Hypernative flagged more than $40 million USD in suspicious transfers out of wallets attributed to Mercado Bitcoin, spread across at least 10 blockchains including Bitcoin, Ethereum, Solana and Tron, Decrypt reported. CoinDesk put the losses at $40 million USD or more based on security firm estimates. The exchange itself has not confirmed a loss figure.

"We identified and swiftly contained a security incident in one of our systems early this morning," Mercado Bitcoin said in a Portuguese-language statement on X. It said deposits and withdrawals were paused as a precaution while its teams investigate, track the assets and coordinate with authorities, the same message it posted on its official help center.

In a follow-up update, the exchange published the destination wallet addresses it had identified on EVM networks, Bitcoin, Solana, Stellar and Tron, so blockchain security firms could track the funds.

Then the stablecoin issuers moved. Tether CEO Paolo Ardoino said on X that Tether had frozen more than 4.5 million USDT linked to the incident, as Decrypt and CoinDesk reported.

How it worked (what we know so far)

This wasn't a clever smart contract bug. Security researchers say the money left through ordinary, signed transfers, per CoinDesk and Cointelegraph. In other words, whoever did this was able to authorize transactions from the exchange's wallets. How they got that access hasn't been disclosed.

No one has been blamed. CoinDesk and Decrypt both note there is no public evidence tying Monday's incident to last week's Binance hack, and Mercado Bitcoin hasn't linked the two.

Context: a brutal week for exchanges

The timing is what makes this story bigger than its dollar figure. Late last week, hackers took roughly $6.3 billion USD from Binance, the largest crypto theft on record. The FBI attributed it to North Korea's TraderTraitor group. Binance reopened withdrawals over the weekend, saw a net $3.64 billion USD leave, and says it has covered about 95% of the stolen amount with its own money, according to CoinDesk and Yahoo Finance.

Markets have noticed. Bitcoin sat around $77,900 USD on Monday, and U.S. spot bitcoin ETFs saw about $643 million USD in outflows on Friday, their biggest single day of withdrawals since June, per CoinDesk and Investing.com.

Why it matters

A $46 million USD breach is small next to Binance's $6.3 billion USD. But Mercado Bitcoin is Brazil's biggest crypto exchange, and its customers can't move their funds right now. That's the part that matters to a regular user: even when an exchange says "no customer losses," your money is frozen until it says otherwise.

The other lesson is about freezes. Tether's quick action shows that some stolen stablecoins can be stopped. But a freeze isn't a refund, and it only works on tokens with an issuer that can blacklist addresses. Bitcoin, ether and most other assets taken in this attack have no such switch.

The money lesson

1. An exchange account is an IOU. When your coins sit on an exchange, the exchange holds the keys. Today, Mercado Bitcoin customers learned that a "pause" can arrive with zero warning, even when nothing of theirs was lost.

2. Size matters, but so does the balance sheet. Binance could cover $6 billion USD from reserves. Smaller platforms may not have that cushion. Before you park money anywhere, ask what happens if it gets hit.

3. Keep a liquidity buffer off-platform. If all your spendable money lives in one app, a withdrawal freeze becomes a cash crunch. Keep your emergency fund somewhere boring and accessible.

4. Self-custody is a skill, not a slogan. Hardware wallets and seed phrase hygiene take some learning. For long-term holdings, it's worth it.

For a deeper look at how crypto investors get burned, listen to Episode 68 - Rug Pulling and Crypto. It's our episode on rug pulls, and the same rule applies here: know who controls the money before you send it.

What to watch next

Whether Mercado Bitcoin confirms a final loss figure, explains how the attacker got signing access, and sets a date to reopen withdrawals. Also watch whether more of the stolen funds get frozen, and whether investigators tie the attack to any known group.

At the time of writing, Mercado Bitcoin's deposits and withdrawals remain suspended with no reopening date announced. This article is for informational purposes only and is not financial advice.

Sources:

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This article may be AI-assisted and is subject to errors and omissions.

Methodical Millions https://methodicalmillions.com
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