A British software engineer has sued HDR Global Trading, the operator of crypto derivatives exchange BitMEX, seeking the return of 324.8 BTC after alleging the company traded with him in the UK without regulatory approval, according to The Guardian and particulars of claim reviewed by Decrypt.
The claim says the Bitcoin was worth £20.4 million on October 1. Using the exchange rates cited in the filing, Decrypt calculated that at roughly $27.2 million.
Lewis Barber, the claimant, says he entered into around 2,294 trades on BitMEX between 2018 and 2022 through five accounts. The lawsuit challenges the 1,053 trades that lost him money.
According to the filing, every one of those transactions was a perpetual swap, a derivative similar to a futures contract but without an expiry date. The claim argues that each trade amounted to a regulated activity and that BitMEX was not authorized to carry out that activity in the UK. On that basis, Barber says the trades cannot be enforced against him under the Financial Services and Markets Act 2000.
Claim says BitMEX did not block UK access
The filing alleges that BitMEX did not restrict access from the UK, allowed new users to select the UK as their country of residence, and ran promotional campaigns worldwide. It points in particular to an advertisement in The Times in January 2019.
The claim also cites a March 2020 warning from the Financial Conduct Authority, which said BitMEX may have been trading regulated investments in the UK without authorization.
Barber is also seeking damages for deceit. He alleges that BitMEX knew it was not authorized, while implicitly representing that it could lawfully trade with him. The claim says his solicitors wrote to BitMEX in December 2025 to rescind the trades.
BitMEX says no claim has been served
The Guardian reported that the case has been filed but has not yet been formally served on BitMEX. A spokesperson for the exchange told the newspaper: 「No such claim has been served on HDR Global Trading Limited.」
BitMEX is also facing a proposed class action in New York that alleges theft of Bitcoin and insider trading. That case names co-founders Ben Delo, Arthur Hayes, and Samuel Reed.
The three co-founders pleaded guilty in 2022 to violating the Bank Secrecy Act through anti-money laundering failures at the exchange. They were pardoned by President Donald Trump in March 2025. BitMEX itself pleaded guilty to Bank Secrecy Act violations in 2024 and was ordered to pay $100 million in January 2025.
Broader UK context around BitMEX
BitMEX shut down on September 23 after announcing in July that it would close.
Decrypt previously reported that Delo donated £36 million to Reform UK in September, the largest single donation in British political history.
Seladore Legal, the law firm representing Barber, said in a statement shared with Decrypt that many other investors may be in a similar position, putting the potential total at hundreds of millions of pounds.
Gareth Keillor, a partner at the firm, said: 「Other UK-based persons may have entered into similar contracts with BitMEX, although whether any individual has a claim will depend on the particular facts and trading history.」
