Bitcoin, created in 2009, was the first decentralized cryptocurrency and remains the most expensive virtual currency worldwide. Other popular cryptocurrencies include: Bitcoin Cash, Ethereum, Dash, Ripple, Litecoin, Maker, Byteball Bytes or Monero. The Asia-Pacific region accounts for the largest share of cryptocurrency users worldwide.
The decentralized control of each cryptocurrency works through Blockchain, a public transaction database that functions as a distributed ledger. The size of Blockchain technology market is projected to grow to over 2 billion U.S. dollars by 2021. The size of Bitcoin Blockchain was around 149 gigabytes as of the fourth quarter of 2017. The largest Bitcoin/Blockchain companies in the world include: Circle Internet Financials, Coinbase, 21 Inc., Ripple, BitFury Group, Blockstream, as well as Digital Asset Holdings.
The inflow of new investors in the second half of 2017 led to a surge in the price of cryptocurrencies. The price of Bitcoin, for example, experienced an increase from about 371 U.S. dollars in January 2016 to over 13 thousand by December 2017. Also, market capitalization of Bitcoin rose from a mere 0.04 billion U.S. dollars in Q1 2012 to over 230 billion U.S. dollars in Q4 2017.
The possibility of taking part in exceptionally high returns offered by the cryptocurrency market resulted in huge interest of investors. The number of users of Coinbase, one of the leading cryptocurrency exchanges in the U.S., increased from 0.4 million in January 2017 to 4.3 million by December 2017.
Cryptocurrencies became so popular that governments and banking regulators decided to intervene and warn that Bitcoin could be the next economic bubble. Some governments even prohibited the trading of cryptocurrencies due to lack of control and market unpredictability. Centralization of hashing power in the hands of a few or in a particular geographical area, are the main challenges affecting the cryptocurrency industry.