Last year, cryptocurrencies burst onto the scene like no other asset class ever has. Over the span of 12 months, the aggregate value of digital currencies soared almost $600 billion, which in percentage terms worked out to more than 3,300%. This was probably the best single-year return for any asset class in history, and we may never see anything like it again.However, not everyone who's made money off the cryptocurrency craze has done so as a traditional investor.