Bitcoin

Recently Bitcoin has risen dramatically in price. Some economists believe that Bitcoin and other digital/cryptocurrencies are merely a fad. Other economists and investors believe digital and cryptocurrencies will replace government issued currencies. Discuss digital and cryptocurrencies. What are they? Why are they becoming popular? What is causing the rapid increase in their popularity and the dramatic increase in the trading price of Bitcoin and other cryptocurrencies?

Requirements: 250 words minimum initial post, 100 words minimum reply