According to Karpelès' LinkedIn page, he worked from 2003 to 2005 at Linux Cyberjoueurs as a software developer and network administrator. Karpelès is a PHP developer.
In 2009, Karpelès founded Tibanne Co. Ltd., a Japan-based bitcoin related technology provider. He is CEO. He was a founding member of the Bitcoin Foundation, created in 2012 with a mission to standardize and promote bitcoin, and served on its board until February 2014.
According to a joint report by Cyrus Farivar of Ars Technica and Pierre Alonso of Le Monde, Karpelès was found guilty of fraud when he was tried in absentia in France in 2010. He also admitted to having "pirated" a server to French authorities. He was sentenced to a suspended year in jail.
Karpelès was arrested on August 1, 2015, by Japanese police on suspicion of having accessed the exchange's computer system to falsify data on its outstanding balance; he was re-arrested and allegedly charged with embezzlement.
Karpelès was released on bail in July 2016, but was required to remain in Japan.
On July 10, 2017, he pled "not guilty" to embezzlement and data manipulation charges.
On March 14, 2019, the Tokyo District Court found Karpelès guilty of falsifying data to inflate Mt. Gox’s holdings by $33.5 million, for which he was sentenced to 30 months in prison, suspended for four years, meaning he will serve no time unless he commits additional offenses over the next four years. The Court acquitted Karpelès on a number of other charges, including embezzlement and aggravated breach of trust, based on its belief that Karpelès had acted without ill intent. Nonetheless, the verdict said Karpelès had inflicted “massive harm to the trust of his users” and there was “no excuse” for him to “abuse his status and authority to perform clever criminal acts.” Karpelès issued a statement saying he was “happy to be judged not guilty” on the more serious charges and was discussing how to proceed with his lawyers regarding his conviction on the falsifying data charge.
Mt. Gox's bankruptcy proceedings will repay creditors in Japanese yen at a price around 483 US dollars per bitcoin (total of 45.6 billion Japanese yen or 400 million US dollars) and it has been reported that this will leave Karpelès, after creditors are repaid, with the bulk of the wealth left over from the difference. Based on the market price at the beginning of 2018 (around $15,000 per bitcoin), the difference is significant, and would leave Karpelès with bitcoins valued at more than 1.4 billion US dollars.
In June 2018, The Tokyo District court approved a petition by creditors to begin civil rehabilitation proceedings in lieu of bankruptcy. As these proceedings are more flexible, creditors expected that they would be compensated based on the current value of their lost coins. On August 23, 2018, creditors were able to begin filing new claims under the civil rehabilitation proceedings. Under the current[may be outdated] schedule, compensation is expected to be distributed in late 2019.[needs update]
^ ab"Declaration of Robert Marie Mark Karpeles"(PDF). US Bankruptcy Court for the Northern District of Texas Dallas Division: 1. Retrieved 13 March 2014. Cite journal requires |journal= (help) The document, signed by "Robert Marie Mark Karpeles", was published by Ars Technica on the Scribd website, and according to Ars Technica is a court document filed in US Bankruptcy Court.