https://www.cnbc.com/2017/10/17/bitcoin-is-speculative-bubble-and-unlikely-to-become-a-currency-ubs.html

Cryptocurrencies like bitcoin are in a "speculative bubble" and are unlikely to become mainstream currencies, according to UBS.

There are over 1,000 cryptocurrencies, bitcoin being the biggest by market capitalization, and many have seen huge rises in value over the past few years. Bitcoin for example is up over 470 percent year-to-date.