UK Trader Sues BitMEX for $27M in Bitcoin Over Unlicensed Derivatives

A UK software engineer is taking BitMEX to court over 324.8 Bitcoin — roughly $27 million at current prices. Lewis Barber argues the exchange had no license to offer derivatives to British users between 2018 and 2022, so every losing trade should be unwound.

The legal hook

Barber's claim targets 1,053 perpetual swap trades that lost money, out of roughly 2,300 total positions he held across five accounts. Under the UK's Financial Services and Markets Act, an unauthorized firm cannot enforce a contract against a retail customer. If the court agrees, BitMEX's operator, HDR Global Trading, would have to return the Bitcoin. The Financial Conduct Authority warned as early as March 2020 that BitMEX might be operating in Britain without permission, yet the exchange kept accepting UK sign-ups and even ran a newspaper ad in The Times.

Why this could spread

Barber's lawyers say other UK traders are likely in the same boat. The potential exposure runs into hundreds of millions of pounds. A win would set a precedent letting anyone who lost money on an unlicensed crypto derivative demand their principal back — a rare path to recovery in an industry where failed platforms usually leave users empty-handed.

BitMEX's baggage

The exchange shut down in September after years of regulatory heat. Its three co-founders pleaded guilty to US Bank Secrecy Act violations in 2022, received a presidential pardon in 2025, and the company itself paid a $100 million fine this January. A separate class action in New York accuses them of insider trading and Bitcoin theft. The UK case adds another layer: it tests whether a platform's global reach shields it from local licensing rules.