He is one of those who have marked the history of bitcoin. Mark Karpelès was the CEO of the cryptocurrency exchange platform Mt. Gox, once a market leader, which nonetheless went bankrupt under the most deplorable conditions. But beyond this notorious label, he also played an important role in the development of Satoshi Nakamoto's project. From "bitcoin baron" to pariah, let's explore the atypical journey of this geek who made global headlines in 2014.