Jack Dorsey, CEO of Square

Louis Ascui | Fairfax Media | Getty Images

Jack Dorsey, CEO of Square

Nearly all users of Square’s Cash payments app can now buy and sell bitcoin on the platform, CEO Jack Dorsey announced Wednesday.

The service will not be available for customers in New York state, Georgia, Wyoming and Hawaii, according to Square’s website.

Shares of Square were up 3.5 percent Wednesday.

The company 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.

Commission-free stock trading app Robinhood announced last week it was rolling out free bitcoin and ethereum trading in five states beginning in February. More than 1 million people have joined the wait list since the announcement.

Robinhood Crypto will also not initially be available in New York, which is one of the toughest states for cryptocurrency trading since it requires a BitLicense.

Coinbase, the leading U.S. marketplace for trading in bitcoin and other major cryptocurrencies, has a BitLicense. The San Francisco-based company has more than doubled its number of users in the last year to more than 13 million around the world. The start-up also charges U.S. transaction fees of 1.5 percent to 4 percent.