the Fundo de Garantia do Tempo de Serviço - FGTS, is a system used to collect funds towards employee's state benefits, and more information on the matter can be found this link.

Once renewed the visa becomes permanent, with proof that the business is still in operation and the investment of the initial cash is still in brazil. 

After becoming permanent, the investor's visa can open the door to the process of naturalization and full residency in brazil.