The findings have led financial regulators around the world to dole out $9 billion (£6.3 billion) in fines to banks and brokerages.
Around 30 individuals have been charged in connection with the probe.
The SFO alleged the six men helped Tokyo-based Hayes in a scam to persuade bank clients to skew interbank borrowing rates to suit his trading position.
Defence lawyers told the jury the defendants were scapegoats for a fundamentally flawed financial system, which was self-governing and in which the establishment knew banks routinely set Libor rates to suit their commercial positions - and that the trial was unfair and unjust.