UK Supreme Court Halts £2.7B Forex Rigging Case Against Major Banks

What Did the Supreme Court Decide?

JPMorgan, UBS, Citigroup and three other major banks have blocked a £2.7 billion ($3.6 billion) mass lawsuit in the UK over alleged foreign-platform rigging, later than the Supreme Court ruled on Thursday that the case lacked merit. The ruling ends a multi-year effort to bring a large opt-out action on behalf of thousands of asset managers, pension funds and financial institutions.

The case was led by Phillip Evans, a former inquiry chair at the UK Competition and Markets Authority, and was based on findings from the European Commission, which fined several banks more than €1 billion in 2019 for FX cartel activity. Regulators in the U.S., UK and Europe have imposed more than $11 over currency-manipulation violations dating back years.

But in its judgment, the Supreme Court agreed with earlier reasoning from the Competition Appeal Tribunal (CAT), finding the underlying claim “fragile” and unlikely to justify a collective opt-out lawsuit.

Investor Takeaway

Why Was the Case Rejected?

Evans’ lawsuit was first blocked by the CAT in 2022, which refused to certify it on an opt-out basis. The tribunal said the case could proceed as opt-in litigation, but acknowledged that doing so would likely end the effort because most claimants were unlikely to participate. The in 2023.

The banks appealed, and the Supreme Court reinstated the tribunal’s original conclusion. Judge Vivien Rose wrote that the CAT “was right to assess the merits of the claim as fragile,” noting that some members of the proposed claimant group may have viable claims but had shown no interest in pursuing them. These claimants represented “a tiny fraction” of the value Evans sought to litigate on their behalf.

The ruling gives the banks a definitive win in a long-running case tied to one of the largest market-manipulation scandals in currency-trading history.

What Does the Decision Mean for Collective Actions in the UK?

The CAT’s original refusal to certify the was suitable for an opt-out structure, where eligible claimants are automatically included unless they choose otherwise. The tribunal found the evidence too fragile to justify sweeping thousands of parties into a collective damages claim.

The Supreme Court’s endorsement of that assessment reinforces the high bar for financial-market class actions under the UK’s competition framework. Even when regulators have previously issued major fines, claimants must still demonstrate clear and measurable harm tied to the misconduct.

While several competition-related class actions have succeeded in recent years, the FX case shows that financial-market claims remain hard to certify when the alleged damage varies widely across participants.

Investor Takeaway

How Did the Banks and Claimants Respond?

UBS and MUFG welcomed the ruling. JPMorgan and Barclays declined to comment, while Citi and NatWest did not immediately respond to requests. For the banks, the decision removes the threat of a multibillion-pound damages case tied to misconduct for which they have already paid heavy regulatory fines.

Evans said he would now consider “what options remain available to pursue justice for those affected.” In his view, an opt-in route would not work: “The practical reality is that opt-in proceedings are unlikely to deliver meaningful redress for the tens of thousands of ordinary individuals and businesses affected by the banks’ unlawful conduct.”

With the opt-out path closed, the lawsuit is effectively finished unless a new claimant group emerges willing to pursue individual or opt-in claims—an outcome the tribunal previously said was improbable.