Cryptocurrencies represent one of the most radical innovations in contemporary economics, but they also pose a challenge to monetary sovereignty and global financial stability. This article analyzes the nature and functioning of cryptocurrencies, their structural volatility, and the macroeconomic and geopolitical implications of financial intermediation. Distinguishing between the speculative component of cryptocurrencies and the innovative potential of blockchain technology, the article highlights how international governance and European regulation can transform an anarchic experiment into an opportunity for economic modernization. Technology, inherently neutral, becomes a factor of risk or progress depending on the institutional framework within which it is embedded.