(Corrects number of investors to 470,000 in third paragraph) SAO PAULO, July 26 (Reuters) - Brazilian financial start up TradersClub on Monday priced its initial public offering at 9.50 reais per share, two sources familiar with the matter said, reaching a valuation of 2.8 billion reais ($541.2 million). The company raised 712.5 million reais in the IPO, one of the sources said. Also known as TC, the company offers services such as news, research and investment chats to 470,000 investors through its app. Shares begin trading on São Paulo Stock exchange on July 28. ($1 = 5.1737 reais) (Reporting by Paula Laier, writing by Carolina Mandl, editing by Chris Reese) Our Standards: The Thomson Reuters Trust Principles.