Jay Merchant, Jonathan Mathew, Philippe Moryoussef, Alex Pabon and Colin Bermingham were convicted following trials for rigging the interest rates used in loans between banks. Their convictions were quashed on Wednesday by the Court of Appeal.
The ruling follows the overturning of convictions for two other former City traders last year, which paved the way for further appeals.
The traders were prosecuted amid public anger during the 2008 financial crisis and were portrayed by prosecutors as symbols of banker greed.
No further details of the court's reasoning have been released.