British software engineer Lewis Barber is suing BitMEX operator HDR Global Trading for the return of 324.8 BTC, alleging unauthorized trading in the UK. The Guardian and particulars of claim identify the lawsuit. The claim values the Bitcoin at £20.4 million on October 1. That value equals about $27.2 million, according to a calculation using the claim's exchange rates.
The claim says Barber entered into around 2,294 trades on BitMEX between 2018 and 2022 through five accounts. Barber challenges the 1,053 trades that lost Barber money. All the challenged trades were perpetual swaps, derivatives similar to futures contracts but without expiry dates. The claim argues that each trade was a regulated activity that BitMEX lacked authorization to conduct in the UK. The claim therefore argues that none of the challenged trades can be enforced against Barber under the Financial Services and Markets Act 2000.
The claim alleges that BitMEX did not restrict access from the UK and allowed new users to select the UK as their country of residence. The claim says BitMEX ran worldwide promotional campaigns, including an advertisement in The Times in January 2019. The claim also cites a March 2020 Financial Conduct Authority warning that BitMEX may have been trading regulated investments in the UK without authorization.
Barber also seeks damages for deceit, alleging that BitMEX knew BitMEX lacked authorization when BitMEX implicitly represented that BitMEX could lawfully trade with Barber. The claim says Barber's solicitors wrote to BitMEX rescinding the trades in December 2025. The Guardian reported that the claim has been filed but has not yet been formally served on BitMEX. A BitMEX spokesperson said, "No such claim has been served on HDR Global Trading Limited."
BitMEX also faces a proposed class action in New York alleging Bitcoin theft and insider trading. The proposed class action 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. President Donald Trump pardoned the three co-founders in March 2025. BitMEX pleaded guilty to Bank Secrecy Act violations in 2024. BitMEX was ordered to pay $100 million in January 2025.
BitMEX shut down on September 23 after announcing in July that BitMEX would close. Delo donated £36 million to Reform UK in September, the largest single donation in British political history.
Barber's law firm, Seladore Legal, said many other investors were likely to be in a similar position to Barber. Seladore Legal put the potential total of similar claims at hundreds of millions of pounds. Seladore Legal partner Gareth Keillor said other UK-based people may have entered into similar contracts with BitMEX. However, Keillor said any individual's claim would depend on the particular facts and trading history.