US Treasury Cuts MEXC Off From US Finance Over $16B Illicit Flows

$16 billion. That is how much money the US Treasury says moved through MEXC Global in transactions tied to sanctions evasion and crime. On Friday, Washington cut the exchange off from the American financial system — and if you hold funds on MEXC, the next 30 days matter.

Key points:

• FinCEN ordered US banks to stop every transfer to or from MEXC, naming it a "primary money laundering concern". The ban bites 30 days after it reaches the Federal Register.
• Treasury says $16 billion in suspect transactions passed through MEXC between May 2021 and May 2026, including $1.5 billion tied to Russian sanctions evasion.
• MEXC is a top-20 exchange with more than $1 billion in daily trades — and it kept dealing with a sanctioned Russian exchange until June 2026, Treasury says.

What the order actually does

The order came from FinCEN, the Treasury bureau that polices money laundering. It tells every US financial institution to stop processing funds transfers to or from MEXC Global. Once the order is published in the Federal Register, the clock starts: 30 days, then the cutoff takes effect.

Treasury did not use a standard sanctions designation. It used a provision of the Combating Russian Money Laundering Act, a tool FinCEN has reached for more often to cut off crypto platforms that sit outside the normal banking system. The label it attached is blunt: MEXC is a "primary money laundering concern" in connection with Russian illicit finance.

Treasury Secretary Scott Bessent put it in plain terms. "Financial institutions cannot have it both ways: Either you support the Iranian regime, or you have access to the U.S. financial system," he said. "Treasury will continue to sever the Iranian regime's economic lifelines and thwart its desperate attempts to circumvent U.S. sanctions using digital assets."

The $16 billion trail

FinCEN's case covers five years, from May 2021 to May 2026. In that window, it says, at least $16 billion in transactions linked to illicit activity moved through MEXC. The biggest named slice is Russian sanctions evasion: nearly $1.5 billion. Another $232 million went in direct transactions with sanctioned entities.

The detail that will hurt MEXC most is the timeline. Treasury says the exchange was still transacting with Garantex, a sanctioned Russian exchange, and its successor Grinex as recently as June 2026 — more than four years after Garantex was first designated. It also processed about $200 million linked to the A7A5 stablecoin and around $22 million that benefited Iran's central bank and its Islamic Revolutionary Guard Corps.

Read also: Thailand to Block Bitget From December 5 — What Happens to Your Crypto?

The controls that were not there

MEXC presents itself as a clean operation. It says it runs anti-money-laundering checks and blocks users in places like Iran and North Korea. FinCEN's answer is that the controls had "severe deficiencies" — the paperwork said one thing, the money flows said another.

Cointelegraph asked MEXC for comment before publishing. The exchange had not replied by publication time. That silence matters, because the scale here is not small. MEXC was founded in 2018 and ranks among the world's 20 largest crypto exchanges. FinCEN puts its daily volume above $1 billion, its reserves near $5 billion, and its token list above 3,000. DefiLlama counted about $4.48 billion in total assets on the exchange on Friday.

My own read is this: An exchange can print all the compliance pages it likes. The real test is who it still does business with — and on Treasury's numbers, MEXC kept doing business with sanctioned exchanges for five years. That is the part traders should remember, not the press release.

Why Treasury picked this fight now

The MEXC order is one move in a wider campaign. Treasury launched Operation Economic Outcast in August to cut off financial firms that help Iran dodge sanctions. Last month, it designated Russia's A7 Network a transnational criminal organization and flagged more than $179 billion in transactions through its ruble-backed A7A5 token, much of it routed through Garantex and Grinex. In June, it sanctioned Nobitex, Iran's largest crypto exchange, which Treasury says processed more than half of Iran's crypto inflows in 2025. In September, it sanctioned Iranian exchange BitBank over alleged bitcoin transfers to the Revolutionary Guard.

The Iran headline hides the Russia case

Here is the part most coverage will miss. The press release leads with Iran, and Bessent's quote is about the Iranian regime. But the order itself rests on Russian illicit finance — that is where the big numbers sit. Treasury names $1.5 billion tied to Russian sanctions evasion against about $22 million linked to Iran's central bank and the Revolutionary Guard. The Russian figure is roughly 68 times the Iranian one. If you only read the headline, you would think this is an Iran story. The money trail says it is mostly a Russia story, with Iran as the reason Treasury chose to act now.

Check where your money sits

Bitcoin was already under pressure this week after Thursday's 6% slide to $75,463, and a crackdown on a top-20 exchange does not help the mood. The practical question for traders is simpler than the politics: Where does your money sit, and can you still move it?

If you hold funds on MEXC, do not wait for the deadline to find out. Check withdrawals now, while the 30-day window is still open, and note three numbers before you act: the date the order reaches the Federal Register, MEXC's own response when it comes, and your balance on the platform. Watch whether other exchanges face the same tool next — Treasury has now used it on a top-20 venue, and the A7 Network case shows it is willing to go after the plumbing behind an exchange too. The cutoff lands 30 days after publication. That is the date that counts.

Read also: Binance, Deribit Cut SignalPlus API Keys After Fake Teams Attack

— BitByLine News Desk

This post is news only, not financial advice. BitByLine never tells anyone to buy or sell crypto — that choice is always yours, and the risk is yours too. Always do your own research first.

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Sources: CoinDesk, Cointelegraph, Decrypt, The Block.