UBS Wealth Management is not a believer in bitcoin becoming a legitimate currency even as the launch of futures lead some investors to believe the cryptocurrency will become a more stable market.

"The bubble to end all bubbles continues. Cryptocurrencies only have value if accepted as currencies. However, they cannot be used for the most important transaction in an economy, and cryptocurrency supply can only rise and never fall (making them a poor store of value)," global chief economist Paul Donovan wrote in a post Monday. "To date, using cryptocurrencies requires (effectively) a simultaneous asset sale and purchase of goods or services."

The economist said in an October report that bitcoin's extreme price volatility detracted from its ability to be a "store of value," which is an essential feature of being a currency.

"A twenty-fold increase in bitcoin prices in just two years, and an absence of any fundamental economic backing, cryptocurrency prices are almost certainly a bubble," he wrote in that report.