Bittrex, the Seattle-based cryptocurrency exchange, has announced that its struck an agreement with a major US-based bank to offer a group of its customers to begin trading in USD pairs, as well as making USD deposits directly to the exchange.

Due to regulation issues, the USD trading pairs are only available to corporate customers in Washington, California, New York and Montana, though Bittrex plans to roll out the offering to all retail customers in the future.

New York based Signature Bank is working with Bittrex to custody dollar-denominated funds.

Bittrex Chief Executive Officer Bill Shihara told Bloomberg in an interview that before the agreement could be made, potential bank partners had to “look and pore through the entire business,” adding:

“They want to make sure that we’ve got robust AML/KYC processes, that we’ve got the right controls on our finances. They do background checks and everything. They really look at our business soup to nuts.”

Banks have mostly been anti-crypto, or at least hesitant to enter the space, even as potential partners to digital currency exchanges like Bittrex. However, Shihara thinks that banks are starting to take a closer look at cryptocurrency as a potential revenue driver, stating “it’s been a long path." Shihara continued:

“It’s not just about banks being able to trust Bittrex. It’s about banks being able to trust crypto in general. And I think it’s really showing that crypto is turning the corner in terms of mainstream acceptance.”

Three USD trading pairs are live now for select corporate customers reigning from the four US states approved by regulators, including bitcoin, Tether, and TrueUSD. No firm date or window has been given for when Bittrex expects to expand to additional customers, only that the firm will do so eventually.