Cryptocurrency is based on blockchain technology. That's a chain of information registration and distribution that is not controlled by any single institution. Bitcoin was considered nothing more than an interesting phenomenon when it first came out in 2009. Technicians and futurists could see the future potential of cryptocurrency in general, but it wasn't drawing much interest as an investment.
But as the years have passed and hundreds of more cryptocurrencies have come and gone, Bitcoin has emerged as the standard-bearer of the currency. This point hasn't been missed by investors and speculators. Many are now coming to see cryptocurrency as an alternative global currency that will eventually replace sovereign currencies such as the U.S. dollar and the euro.