The fee that eats the balance by the deadline

BitMEX stopped trading on 23 September, eleven years after it opened. The company announced the closure on its own blog on 23 July, and CoinDesk reported it the same morning. It is one of five offshore crypto exchanges that announced or began winding down in 2026.

AscendEX ceased operations on 1 July. Exmo.com confirmed its own wind-down on 14 July. BitMart announced on 26 July and its platform closes 31 January 2027.

CoinEx announced in mid-September and closes 22 December 2026. Exmo is a different case from the other four: Finance Magnates reports it deducted a 29.4 percent shortfall from every client balance and issued a non-tradable token instead, after a British sanctions designation of group entities reported by FinanceFeeds and disputed by the company.

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The closings are not the interesting part. The fees are.

The number that matters

Five percent a month.

That is the custody fee in CoinEx's notice. It applies to tether not withdrawn by the 22 December deadline, which the notice says passes into independent custody. It is tether only because by then there is nothing else to charge: from 02:00 UTC on 29 September, CoinEx sells the non-tether assets that have a market outside its own books, returns the net proceeds to spot accounts as tether, and gradually delists the ones with no outside market at all.

The charge is flat: five percent of the original balance recorded at the end of the withdrawal period, not five percent of what remains.

BitMEX charges for the same thing, and the size depends on which BitMEX document you read. "The closure blog post words the charge as one percent a year, charged monthly, or fifty dollars equivalent for accounts with no more than that amount, which reads as a floor for tiny balances."

The support page, as read by Unchained and news.bitcoin.com, renders it as the greater of fifty dollars a month or one percent a year. Both readings are in circulation.

On ten thousand dollars that is about a hundred dollars in the first year, or about six hundred, since a fifty-dollar monthly floor binds on any account under roughly sixty thousand dollars. CoinEx's five percent a month on the same balance is about six thousand in the first year.

So the gap is either about ten times or about sixty times, and the firm that could settle it is the firm that is leaving.

CoinEx's claims window closes 22 August 2028. From 22 December 2026 that is twenty months, and twenty months at five percent of the original balance is one hundred percent. The rate and the two dates meet at zero, so a claim filed on the last permitted day is a claim on nothing. CoinEx has not said it planned the fee that way.

CoinEx's notice calls the window a 90-day withdrawal period ending 22 December, and ninety days back from that date is 23 September. Withdrawals actually opened on 15 September, which makes the real window 98 days. The label is shorter than the thing it labels.

How the fee works

All five held customer coins as a custodian. Neither company describes the leftover balance as a deposit, and neither cites deposit insurance.

A platform in wind-down publishes a withdrawal window, moves whatever is left into a custody or dormant-account arrangement, and takes the fee from the customer's own balance, month after month. No invoice arrives. "BitMEX's support page says a balance never goes below zero and that nothing is owed once it is depleted, so nobody ends up a debtor." The asset just gets smaller until it is not there.

What a New Jersey bank account does instead

New Jersey publishes the opposite arrangement. Its Unclaimed Property Administration says it never charges a fee to search and claim, and holds property in perpetuity or until a valid claim is submitted. Under state law a checking or savings account is generally treated as abandoned after three years without a deposit or withdrawal, and the holder must first send a letter by certified mail, not more than 120 and not fewer than 60 days before it reports.

Ownership does not change when the money reaches the state. That is standing New Jersey Treasury guidance; other states write their own rules, and this is policy explained, not legal guidance.

One system spends a stamp to find the customer and charges nothing to hand the money back. The other deducts monthly until there is nothing to hand back.

What to watch

Published: CoinEx closes withdrawals 22 December 2026, it converts or delists everything that is not tether from 02:00 UTC on 29 September, and BitMart's platform ceases 31 January 2027. Not published: whether BitMart attaches any leftover-balance fee, and what BitMEX's rate becomes; its announcement says the fee will increase over time, to be communicated in advance.