(Bloomberg) -- Wintermute Trading Ltd., one of the biggest cryptocurrency market makers, was accused in a proposed class-action lawsuit of helping former Celsius Network Ltd. Chief Executive Officer Alex Mashinsky dupe investors in his now-bankrupt crypto lending firm.Most Read from BloombergTitanic Sub Crew Dead After Vessel’s Catastrophic ImplosionFive-Star Hotel Guest Leaves Without Paying After 603-Night StayThe Big Names That Got Backstop for Billions in Uninsured SVB DepositsThese Are the