Former City trader Tom Hayes has been found guilty at a London court of rigging global Libor interest rates.
He was sentenced to 14 years in prison for conspiracy to defraud.
The 35-year old is the first individual to face a jury trial for manipulating the rate, which is used as a benchmark for trillions of pounds of global borrowing and lending.
Many of the world's leading banks have paid heavy financial penalties for tampering with the key benchmark.
The jury found Hayes guilty on all eight charges of conspiracy to defraud.
From Mark Broad, at Southwark Crown Court
Hayes stood impassively as the foreman on the jury read out all eight guilty verdicts.
His wife noted down the verdicts as they were read out.
At one point, he shook his head and looked across at his wife, mother and stepfather in the public gallery.
Hayes held his head in his hands while his lawyer read out a list of mitigating factors.
Hayes was sentenced to 14 years, half to be spent in custody before any possibility of release on licence.
Justice Cooke said Hayes was the "centre and hub" of the manipulation.
He said: "You succumbed to temptation because you could... To gain status, seniority and remuneration," adding that Hayes' actions were "dishonest and wrong".
The case was brought by the Serious Fraud Office, which said Hayes set up a network of brokers and traders spanning 10 financial institutions and cajoled or bribed them to help rig Libor rates for profit.
During the trial, jurors were told that Hayes promised to pay a broker up to $100,000 to keep the Libor rate "as low as possible".
It took the jury one week to arrive at the verdicts.
Defence barrister Neil Hawes asked the judge to take into account the prevalence of Libor manipulation at the time, and also that Hayes had been diagnosed with Asperger's syndrome, a condition on the autism spectrum.
Mr Hawes also said that managers and senior managers at Hayes' bank knew of, and in some cases condoned, Libor manipulation.
Hayes, a former star trader originally from Fleet in Hampshire, rigged the Libor rates daily for nearly four years while working in Tokyo for UBS, then Citigroup, from 2006 until 2010.
Citigroup says it has no comment about the verdicts. UBS has said it was not a party to the case.
Hayes's trading activities were based around movements in the Libor rate - the London interbank offered rate.
It is an interest rate used by banks around the world to set the price of financial products worth trillions of pounds.
Rigging even minor movements in the rate can result in bumper profits for a trader manipulating the rates, or the rate can be moved simply to make a bank look more creditworthy.
During the trial, the court heard that manipulating the Libor rate was so commonplace that an offer of a Mars bar could get it changed.
Hayes told a fellow trader: "Just give the cash desk a Mars bar and they'll set wherever you want."
Hayes confessed, saying that he did not want to be extradited to the US.
He claimed that the manipulation was widespread.
Hayes initially co-operated with investigators, confessing to the manipulation.
But four months after he was charged in 2013, he changed his legal team, and his plea.
He pleaded "not guilty" to the charges, resulting in the trial, which began on 26 May.