A formal complaint has been made by the Managed Fund Association against the London Metal Exchange over its cancellation of nearly $4bn in nickel trades on 8 March.

In an 8 June letter to the LME, the hedge fund group — representing 150 hedge funds managing nearly $2.6tn in assets — said that “the LME has undermined confidence in its ability to oversee markets by failing to perform its regulatory obligations to maintain an orderly market, manage conflicts of interest and protect investors in the nickel market”.