Bitcoin, the leader in cryptocurrencies, is gaining credibility and is posing as a competitor to traditional currencies. A real threat to the euro and the dollar. The price of bitcoin, which has been on an upward curve for several months, soared by 20% in the following 48 hours. The internet currency has crossed the record value of $ 50,000 driven by an unprecedented craze. The car manufacturer Tesla has just invested $ 1.5 billion in bitcoin. This sum represents about 8% of the cash of Elon Musk's company. Last October, Square, the payment company created and run by Twitter boss Jack Dorsey, invested $50 million in bitcoin. The company MicroStrategy, specialized in data analysis software, has also invested significant sums in bitcoin, in several times, during the year 2020 and in 2021. Last December, his boss Michael Saylor announced that his company held 40,000 bitcoins. In January 2021 the famous investment fund BlackRock, the world's number one asset manager, affirmed its intention to include certain bitcoin derivatives in the list of assets that the fund could take in the portfolio. Also, the bank BNY Mellon announced in early February the creation of a new division dedicated to cryptocurrencies. The American company PayPal which has developed a globally successful payment solution, has unveiled its intention to accept bitcoin transactions on its platform. Mastercard has also just accepted cryptocurrency transactions on its network. Jack Dorsey, and billionaire rapper Jay-Z, husband of singer Beyoncé, have also just invested 500 bitcoins in this ambitious project that puts traditional state currencies such as the euro or the dollar in competition. "Bitcoin is a speculative asset. But it was conceived from the outset as a currency. It's a digital currency project," says Odile Lakomski-Laguerre, a lecturer in economics at the University of Picardy. For her, bitcoin is now in the third phase of its evolution, a phase of credibility.