Nu Pagamentos, as Nubank is formally known, posted a net income of 76 million reais ($13.7 million) in the period between January and June, its first semester in the black. In the same period a year earlier, Nubank had a loss of 95 million reais.
The fintech is backed by Warren Buffett's Berkshire Hathaway Inc.
Nubank's first profit for a full semester comes as Latin America's most prominent fintech is eyeing an initial public offering in the United States by the beginning of 2022, with a valuation over $55 billion.
The results do not include Nubank's operations in Colombia and Mexico, although Brazil is the fintech's largest market by far.
Chief Financial Officer Guilherme Lago said in the statement that Nubank's total payment volume doubled from a year earlier to 92 billion reais, adding the fintech's clients have used their credit cards more often.
Its loan book, according to Brazil's central bank data, ended June at 23 billion reais, also roughly doubling from a year earlier.
Nubank added more than 8 million new clients since December, Lago said.
(Reporting by Carolina Mandl; Editing by Aurora Ellis)