Gemini Trust, a virtual currency company, has been approved by New York's Department of Financial Services to expand its operations into Washington state.

As of last week, customers in Washington can buy, sell or store Bit coin and Ether — another digital currency on a network known as Ethereum — using the Gemini exchange, which allows customers to trade virtual currency.

New York-based Gemini Trust was started by Cameron and Tyler Winklevoss, both of whom sued Facebook founder Mark Zuckerberg claiming that he stole the idea of the social-networking platform from them.