Supreme Court hears rate-rigging appeal

The Supreme Court is set to hear an appeal by former traders Tom Hayes and Carlo Palombo as they challenge their convictions for rate-rigging. The case raises questions about the definition of LIBOR and EURIBOR, as well as the potential impact of differing legal interpretations between the UK and the US.

Commenting ahead of the hearing, Maia Cohen-Lask, partner at Corker Binning, noted that while the question of how LIBOR and EURIBOR were defined is now of historical significance, the case could have wider legal implications. “The Supreme Court case appears to be considering, once again, the correct definition of LIBOR / EURIBOR, and whether it incorporated a range of potential borrowing rates. The answer to this question is, in 2025, largely of historic interest, with prosecutions for manipulation of these rates now a thing of the past.”

She highlighted that a key issue is whether UK courts should consider US legal interpretations in financial crime cases. “The potential question in this case with wider public significance arises from the perceived conflict between the approach taken by US courts and UK courts, and what if any significance that has for individuals who seek to rely on the US courts’ interpretations of international financial practice in their UK defence. It is unclear whether the Supreme Court will tackle the latter question head-on, the Court of Appeal having side-stepped the issue by suggesting that the two jurisdictions were in fact considering different questions. However, it is consideration of the cross-jurisdictional impact question, not the LIBOR definition question, which has the potential to have ramifications for future prosecutions.”

Legal experts and financial professionals will be watching closely to see if the court addresses the broader implications of jurisdictional conflicts in financial cases.