An SEC filing (document) reveals the company is officially seeking an initial public offering, as well as financial information: In the first half of 2015 Square took losses of $77.5 million on revenue of $560.5 million. In 2014, the company reported gross payment volume of $23.78 billion. The filing reveals retail the biggest source of transactions for the company constituting 21 percent of its gross payments volume. Other sectors include services, food, beauty, contractor, and transit. The filing also says Dorsey’s role as the CEO of Twitter and Square is a risk factor:
Jack Dorsey, our co-founder, President, and Chief Executive Officer, also serves as Chief Executive Officer of Twitter. This may at times adversely affect his ability to devote time, attention, and effort to Square.