Tether Freezes 4.5M USDT Tied to Mercado Bitcoin Breach

Tether has frozen more than 4.5 million USDT linked to the security breach at Brazilian exchange Mercado Bitcoin, chief executive Paolo Ardoino said on Monday, Nov. 2. "Tether froze more than 4.5M USDT related to this security incident," Ardoino wrote on X.

For Mercado Bitcoin customers, the freeze does not reopen anything. The exchange suspended deposits and withdrawals after it said it had contained an incident in one of its systems. No reopening date has been confirmed. Mercado Bitcoin has said customers suffered no harm, that no data leaked and that the suspension is a precaution.

A Freeze Is Not a Refund

Ardoino's post described a freeze. It did not say the tokens had gone back to Mercado Bitcoin, and whether they will is not yet known.

The 4.5 million USDT is also a small slice of what has been flagged. Security firm Hypernative put preliminary estimates of suspicious transfers from wallets attributed to the exchange above $40 million, spread across several blockchains. Mercado Bitcoin has not confirmed that figure or given a total of its own. Other analysts cite different numbers, so the size of the loss is still an open question.

Suspect Addresses Span Five Networks

Mercado Bitcoin published suspicious destination addresses on Ethereum-compatible (EVM) networks, Bitcoin, Solana, Stellar and Tron. Its EVM entry lists the address 0xe485e7A70b1131216Cb47CA4555c4Bbb2C742478.

That spread matters for anyone hoping the money comes back. A stablecoin issuer can act on its own token, as Tether did here. Funds sitting on several chains in several assets give the attacker more than one route out, and the exchange has not said how much of the flagged total sits in tokens an issuer could freeze.

Tether Is Also an Investor in the Exchange

Tether is not a neutral party in this story. The stablecoin issuer announced a $20 million strategic investment in Mercado Bitcoin in July, to support the exchange's push into tokenization, payments and other digital financial services.

That does not make the freeze any less real, but it is worth keeping in mind when Tether is the one announcing good news about the exchange. Tether has used the same power on other thefts, including the CryptoBilis Ledger drain.

Three things will decide how this ends for Mercado Bitcoin users: a confirmed loss figure from the exchange, a date for withdrawals to restart, and whether the frozen USDT is returned rather than simply held.