Mercado Bitcoin, a large Brazilian crypto exchange, suspended crypto deposits and withdrawals on 2 November 2026 after finding a security incident in one of its systems. A security firm flagged more than $40 million in suspicious transfers across at least ten blockchains, including Tron and Ethereum. On 4 November the exchange pledged to use company funds to restore affected assets and announced a phased reopening that starts with view-only access. For merchants, the lesson is about where money waits after a sale: a balance on one exchange can be out of reach for days, without warning.
What happened?
| Date (2026) | Event | Source |
|---|---|---|
| 2 November | The exchange says it identified a security incident in one of its systems and temporarily suspends deposits and withdrawals. It says no customer lost money and no data leaked | Decrypt, crypto.news |
| 2 November | Security firm Hypernative flags more than $40 million in suspicious transfers that may be linked, in a preliminary analysis across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron. The exchange hasn't confirmed that figure. It publishes the destination addresses it identified on five networks so they can be tracked | Decrypt |
| 2 November | Tether's CEO says it froze more than 4.5 million USDT tied to the incident | Decrypt |
| 4 November | More than $15 million has been frozen with help from the industry. The exchange pledges company funds to replenish affected assets. Access returns in phases: first viewing balances, statements and holdings on the website, then transfers, withdrawals and trading in later phases, subject to independent security testing. No dates are given for the later phases | Cointelegraph |
The exchange hasn't given an estimate of the assets involved. Cointelegraph reports that blockchain analysts, whom it doesn't name, put the loss at more than $46 million, and that funds left both the company's hot wallets and customer deposit addresses. How the attackers got in hasn't been disclosed.
In the exchange's words, as quoted by Decrypt: "As a preventive protection measure, deposits and withdrawals are temporarily suspended."
What this means for merchants
- An exchange balance isn't cash in hand. Merchants who sell USDT or BTC for local money through a single exchange can be locked out while it investigates. This is the second large exchange pause in about a week, after Binance at the end of October.
- USDT can be frozen by its issuer. Tether's quick freeze helped here. The same power means USDT at an address linked to a theft can be frozen.
- Recovery comes in phases. Seeing your balance comes first; withdrawing it comes later, on a timetable the exchange sets.
What should a merchant do now?
- 1Use more than one off-ramp. Keep accounts at two or more exchanges or brokers you can actually sell through, set up and verified before you need them.
- 2Don't let balances sit at an exchange. Move what you don't need to sell soon to a wallet you control, on a schedule.
- 3Be careful with unusual incoming payments. A large or unexpected payment from an unfamiliar source this week is worth a second look before you ship anything valuable. The exchange's published addresses are linked from the crypto.news report.
- 4If you use Mercado Bitcoin: expect view-only access first. There is no date yet for withdrawals, so plan cash flow without that balance.
- 5Ask your payment provider how long funds wait with it, and how you withdraw if one of its exchange partners pauses. Settling to your own wallet on a schedule is covered in crypto settlement for developers.
Frequently asked questions
Did Mercado Bitcoin customers lose money? On 2 November the exchange said no customer had lost money, and on 4 November it pledged company funds to replenish affected assets. Those are its statements; final figures haven't been published.
Is my USDT safe if it passed near a hacked address? Tether can freeze addresses it links to a theft. Coins received in a normal sale from an unrelated customer are not usually affected, but a payment that comes straight from a flagged address may be.
When can Mercado Bitcoin customers withdraw? No date has been given. The plan published on 4 November starts with view-only access and adds withdrawals after independent security testing.
Sources
- Report on the withdrawal halt, Hypernative's estimate and Tether's freeze, Decrypt, 2 November 2026
- Report on the exchange's statement and the addresses it published, crypto.news, 2 November 2026
- Mercado Bitcoin says phased reopening to begin Monday, will cover losses, Cointelegraph, 4 November 2026