Bank stocks come in all shapes and sizes. But which one offers the most long-term upside right now? It's a bank stock most investors have never heard of: Nu Holdings (NYSE: NU).

If you want to maximize your long-term profit potential, this stock is for you.

This stock could be a monster

Nu isn't your average bank stock. The company was founded in 2013 for a singular reason: to capitalize on the massive potential of Latin America's banking industry.

For years, Latin America -- which boasts a population of 650 million -- had a banking industry largely dominated by a handful of competitors. These old-school banks charged customers high fees for simple services, with the integration of technology far lagging more developed markets like the U.S. or Europe.

Nu was launched to take on these stodgy competitors with a digital-first approach. The start-up allowed customers to open and use their bank accounts, credit cards, and other financial products straight from a smartphone app, something few competitors were doing at the time.

"At first, the competition failed to take Nubank seriously," writes Doug Leone, a partner at Sequoia Capital, a legendary venture capital firm that eventually backed the project. "[T]hey didn't understand the deep technological work involved in the backend of the deceptively simple user experience, and thought the company was nothing more than an app."

Fast forward to today, and Nu is dominating the markets it operates in. More than half of all adults in Brazil, for instance, are Nu customers. The company has entered the Colombian and Mexican markets as well, which have also experienced rapid adoption. For example, deposits in its Mexican division grew from $0 to $1 billion in under 7 months.

While incumbents are racing to catch up, Nu has a strong first-mover advantage. Its business model is lean, meaning it can deliver new products faster and more efficiently than the competition, all with higher profitability. While the competition is stuck operating hundreds of physical branches focused on basic financial services, Nu has expanded into innovative products, like NuCripto, which brought crypto investing to its entire user base in 2022.

Nu now has a proven record of growth and a reputation for keeping its customers engaged with new products and services. More than 80% of its customer base, for example, generates revenue monthly for the company. Nu could enter more than a dozen new countries over the coming years. And while these don't have the scale or income levels of Brazil, Mexico, or Colombia, Nu shouldn't have any trouble growing. Analysts expect sales to grow by nearly 25% next year alone.