Digital currency of its creators. "Forbes" writer Tim Worstall has written that the value of bitcoin is largely derived from speculative trading. Bitcoin has also been criticised for its energy inefficient SHA-256-based proof of work. Digital currency Digital currency (digital money, electronic money or electronic currency) is a type of currency available in digital form (in contrast to physical, such as banknotes and coins). It exhibits properties similar to physical currencies, but can allow for instantaneous transactions and borderless transfer-of-ownership. Examples include virtual currencies and cryptocurrencies and central bank issued money accounted for in a computer database (including digital base money). Like
Reserve currency before the beginning of the worldwide credit crunch related recession and Eurozone crisis, which harmed the euro and slowed its adoption. Since 2009, the reserve currency use of the euro has continued to drop, down to 23.9 percent in 2013. The Dutch guilder was the "de facto" reserve currency in Europe in 17th and 18th centuries. The United Kingdom's pound sterling was the primary reserve currency of much of the world in the 19th century and first half of the 20th century. The emergence of the USA as an economic superpower, and the establishment of the U.S. Federal Reserve System