Jérôme Kerviel will walk out of jail on Monday, a Paris court ruled on Thursday in a move that will reduce the rogue trader's stay behind bars to just over 110 days.
The former Société Générale trader, who almost brought his former employer to the brink of collapse after losing €4.9bn by placing unauthorised trading positions, has won an appeal which will see him wear an electronic tag and placed under supervision.
Kerviel was put in prison in May to serve a three-year sentence after he gave himself up to French authorities following an unsuccessful campaign to have the criminal charges quashed.
David Koubbi, Kerviel's lawyer, said his client would be released from the prison just south of Paris, where he is being held, on Monday, on the condition he wears an electronic bracelet and abides by the terms of his release.
This includes a curfew that would require him to be at home between 10pm and 7am every weekday night, according to France 24, the Paris-based international news channel.
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Kerviel turned himself into French police in May after a three-month pilgrimage from Rome back to the French border aimed at drawing attention to his plight.
Kerviel always admitted making the rogue trades but insisted he was the victim of a system that allowed his activities as long as they made money for his bank.
In March, the appeals court found him guilty on criminal charges but overturned the €4.9bn in damages he had been ordered to pay back to SocGen.
Many in France see the former trader as a victim fighting an overbearing financial system. A poll taken in 2008 showed 77 per cent of French respondents viewed him as a "victim". His story has inspired a fan club, a comic book called Le Journal de Jérôme Kerviel and a film called Avis de Tempête (Storm Warning).
He was convicted in 2010 and sentenced to five years in prison, with two years suspended.