Twitter and Square CEO Jack Dorsey is a big believer

Bitcoin will overtake the US dollar within a decade, according to Twitter and Square CEO Jack Dorsey.

"The world ultimately will have a single currency, the internet will have a single currency. I personally believe that it will be bitcoin," Dorsey said. It will happen "probably over ten years, but it could go faster."

Bitcion is up about 1.5% to $9054 today in a continuing rebound after hitting $7580 early in the week.

Dorsey is most-famous for founding Twitter but Square is a payment processing company and wants to make Bitcoin more accessible. At the same time, he acknowledged that Bitcoin needs to improve before it go mainstream.

"It's slow and it's costly, but as more and more people have it, those things go away. There are newer technologies that build off of blockchain and make it more approachable," Dorsey said.