A currency trader from the Cartel chatroom -- the instant-messaging group the U.S. government named in wringing guilty pleas from five global banks -- has been helping prosecutors who are trying to build foreign-exchange manipulation cases against individuals, according to two people familiar with the matter.
The cooperator, they said, is Matt Gardiner, a former UBS Group AG trader known in the chatroom as Fossil. U.S. officials are confident they will be able to charge individuals over currency-rate manipulation, possibly as soon as this summer, a third person said.