Billionaire Alex Gerko, one of the UK's largest taxpayers and founder of XTX Markets, is reportedly closing down HFFX LLP, the investment fund at the center of a recently lost tax battle at the UK Supreme Court. The fund, which operated from 2010 to 2015 while Gerko was at GSA Capital Partners, involved deferred trading profits that the court ruled should be subject to income tax. The total tax bill in question for Gerko and 12 former colleagues from HFFX LLP is approximately £22.5 million ($30.2 million).
The Supreme Court ruling on June 17, 2026, concluded an 11-year legal dispute, affirming that the deferred payments to traders were taxable as miscellaneous income, despite the taxpayers arguing they were capital in nature. Gerko had previously accused HMRC of "massive double taxation," noting that funds were initially taxed at corporate rates within HFFX before staff faced income tax on their individual payouts. HMRC, however, welcomed the decision, stating its commitment to pursuing those who avoid paying their fair share of tax.
Gerko, with an estimated net worth exceeding $17 billion, paid £331.4 million in taxes last year. His company, XTX Markets, established in 2015 after he left GSA Capital, is a major player in quantitative trading and market-making, reportedly distributing a record £2.2 billion ($3 billion) dividend to its parent company in 2025. The closure of HFFX LLP marks the final chapter in the contentious tax case, reinforcing HMRC's stance on deferred compensation structures.
