AQR Capital Management, DRW Commodities, Flow Traders, Capstone Investment Advisors, and Winton Capital Management made the application Sept. 7 at the London Commercial Court. The investment firms are seeking disclosure of two certain documents related to the market halt, which was instigated by a short squeeze that drove the three-month nickel price over $100,000/mt.

“We regard that application as without merit and we look forward to setting out our arguments in due course opposing the application,” an LME spokesperson said.

That came after the exchange suspended the nickel market and cancelled some nickel trades, "causing significant losses for many market participants," the petitioners said in a joint statement emailed.

“In light of the circumstances of the suspension, the extraordinary step of cancelling trades agreed upon in these circumstances and the [LME’s] own piecemeal disclosures of its actions, the applicants seek disclosure of certain documents from the [LME] to assess their legal position,” the petitioners said.

The LME has already been sued for a collective $471.7 million by the likes of Elliott Management Corp and Jane Street Global Trading over the disruption.

An independent probe into the trading suspension by management consulting firm Oliver Wyman is expected to wrap up in December.