UK Investor Sues BitMEX for 324.8 BTC in London Court

A UK software engineer is suing BitMEX operator HDR Global Trading Limited in London's Commercial Court. He wants 324.8 BTC returned. The trades he is contesting, he argues, were regulated activity the exchange was never authorised to carry out in the UK.

Lewis Barber filed the claim at the High Court. It contends that contracts of that kind are void under the Financial Services and Markets Act 2000. On that reading, consumers would be entitled to restitution of the bitcoin they lost on them. The claim has not yet been served on BitMEX.

BitMEX's only public answer so far is procedural. "No such claim has been served on HDR Global Trading Limited," a spokesperson said. The company has not responded publicly to the substance of the case, and the allegations are untested.

The Claim Challenges 1,053 Perpetual Swaps

The claim's arithmetic is specific. Barber traded on BitMEX between 2018 and 2022 from five accounts, around 2,294 trades in all. The claim challenges the 1,053 of those that lost him money. Every one of those was a perpetual swap. That is a derivative similar to a futures contract, with no expiry date.

The argument is about permission rather than outcomes. Each of those trades was a regulated activity, the claim argues. BitMEX was not authorised to carry out that activity in the UK, so the trades cannot be enforced against him. His solicitors wrote to BitMEX in December 2025 rescinding the trades. He separately claims damages for deceit. The claim alleges the exchange knew it was not authorised when it implicitly represented that it could lawfully trade with him.

The loss is stated two ways across reports of the claim: as 324.8 BTC and as £20 million. No page read for this article reconciles the two. The claim puts the bitcoin at £20.4 million as of 1 October.

What the FCA Warning and Ban Cover

The claim points to how BitMEX reached UK users. Barber's statement of claim says BitMEX "conducted promotional campaigns on a worldwide basis and did not exclude the United Kingdom from their reach." It says HDR placed at least one advertisement in The Times, published on 3 January 2019. It cites a warning the FCA issued on or around 3 March 2020. That warning said BitMEX may have been conducting trading in regulated investments in the UK without authorisation.

That warning is still published on the FCA's site: "This firm is not authorised by us and is targeting people in the UK." The page adds that users would not have access to the Financial Ombudsman Service or protection from the Financial Services Compensation Scheme.

The FCA's general position is that almost all firms must be authorised or registered by it. That covers firms offering, promoting or selling financial services or products in the UK. It banned the sale, marketing and distribution of crypto derivatives and ETNs to retail consumers from 6 January 2021. The ban covered products referencing unregulated transferable cryptoassets, and it covered CFDs, options and futures for firms acting in or from the UK. The claim rests on authorisation rather than on that ban. Its case is that the swaps were regulated activity needing FCA authorisation at the time he traded them.

At the time of the ban, Sheldon Mills, then the FCA's interim executive director of strategy and competition, said:

Significant price volatility, combined with the inherent difficulties of valuing cryptoassets reliably, places retail consumers at a high risk of suffering losses from trading crypto-derivatives. We have evidence of this happening on a significant scale.

Seladore Says Other UK Traders May Have Similar Claims

Barber's firm, Seladore Legal, says he may be one of thousands of non-professional UK investors who lost money on BitMEX derivatives. It says those derivatives were sold in breach of FCA rules and consumer protection law. It puts the potential bill at hundreds of millions of pounds if the claim succeeds.

Gareth Keillor, a partner at the firm, said:

Lewis's case is that BitMEX entered into these transactions without the authorisation required under UK law, and that the Financial Services and Markets Act therefore entitles him to recover the bitcoin he lost, or equivalent damages.

He added that other UK-based persons may have entered into similar contracts with BitMEX. Whether any individual has a claim depends on the particular facts and trading history. Seladore also publishes a BitMEX claim registration form for people who traded crypto derivatives, with loss bands running to over £5 million. It states that registering does not commit anyone to bringing a claim.

BitMEX closed on 23 September 2026. It announced the shutdown in July, after what it called a strategic review by the board of HDR Global Trading Limited. In its closure post, the exchange said it invented the 100x leverage perpetual swap. It also said it had lost no funds to hacks across more than 11 years of operation.

Elsewhere, BitMEX faces a proposed class action in New York alleging theft of bitcoin and insider trading. It names co-founders Ben Delo, Arthur Hayes and Samuel Reed, and the company has said it will defend it. In 2024 it pleaded guilty to Bank Secrecy Act violations over anti-money-laundering and know-your-customer failures. In January 2025 it was sentenced to a $100 million fine and two years' probation, per the US Attorney's Office for the Southern District of New York. Delo gave £36 million to Reform UK in September, reported as the largest single donation in British political history.

The next thing to watch is service. Until the claim is formally served on HDR Global Trading, BitMEX has filed nothing on the substance. The 1,053 trades remain allegations rather than findings.