Shares of Square briefly rose 4 percent before closing 3 percent higher Wednesday. Square began testing bitcoin trading on its Cash app in mid-November and rolled out access to more customers in December. Customers are limited to $10,000 in bitcoin purchases a week through the app, but there is no limit to the amount that can be sold, Square said on its website. Users cannot send bitcoin directly to other Cash users. Square said it will hold the bitcoins on behalf of its customers. The company also said it would not add other fees to bitcoin transactions and would calculate prices by looking across major exchanges.

https://www.cnbc.com/2018/01/31/jack-dorseys-square-launches-bitcoin-trading-for-all-cash-app-users-except-those-in-four-states.html