Using the benchmark of the U.S. Dollar Index, a comparison against a basket of major currencies
the dollar gained 8.3% throughout the 2015.
Despite this strength, the best performing currency in 2015 was NOT the dollar.
In fact, the top currency of 2015 is likely to be considered the furthest thing from the greenback.
Bitcoin, a digital and decentralized cryptocurrency, staged a late comeback in 2015 to overtake the dollar by a whopping 35% by the end of the year.