Nubank, the largest digital bank in Latin America, is facing a "name crisis" due to new regulations by Brazil's central bank. The new rules prohibit companies without a banking license from using "bank" in their brand names. To retain the "Nubank" name, the company is exploring the acquisition of a small bank with a formal banking license, with Banco Digimais as a potential target. Nubank currently serves 110 million users in Brazil and has a market valuation exceeding $80 billion, placing it under higher regulatory scrutiny.