Most investors first noticed Nu Holdings (NU -3.53%) for its eye-popping growth story. In just a few years, the Brazilian digital bank amassed more than 120 million customers across Latin America and became the world's largest digital banking platform.

But while the headlines focus on its rapid rise, a quieter -- and perhaps more important -- story is unfolding. Nu is steadily transforming from a flashy fintech into a full-scale banking empire.

Customer uses a smartphone for online banking.

Image source: Getty Images.

Building a profitable core

In fintech, scale often comes at the expense of profitability. Nu is proving it can have both. In 2024, Nu generated $11.5 billion in revenue (up 58% year over year) and $2.0 billion in net profit. It also achieved a 28% return on equity -- levels that rival or even surpass the best-run banks. It's rare for a company to be able to grow at high double digits and still deliver solid profits.

Lending remains a key driver. The company's loan book reached $21 billion in 2024, growing 45% year over year on an FX-neutral basis. Its 90-plus day delinquency rates have trended lower after peaking at 7.2% in the third quarter of 2024, steadying at 6.6% in the second quarter of 2025. In other words, while Nu has been scaling its credit business, it hasn't let losses get out of control, suggesting that management is keeping an eye on risk management as well.

With a profitable core, Nu is well-positioned to further capitalize on its strengths -- in acquiring and delighting customers -- as it evolves into a diversified financial services giant.

Deepening relationship with customers

Historically, Nu has been highly successful in acquiring users thanks to its simple and straightforward offerings to solve customers' pain points. But that's just part of the story. The bigger story now is how it's expanding wallet share.

Most customers start with a no-fee credit card or digital account. Over time, Nu cross-sells loans, savings, investments, and insurance. That strategy is paying off: average monthly revenue per active customer has grown from $4 in the second quarter of 2021 to $12 in the second quarter of 2025, a threefold increase.

The mix is broadening, too. Nu is pushing further into asset management and protection products -- two areas where penetration in Latin America remains low. These adjacencies not only boost margins but also make customers stickier, making revenue and profits more recurring in the future.

As CFO Guilherme Lago put it, future growth in Brazil will come "less from adding customers, and more from deepening relationships." Nu is doing just that as it keeps its growth engine humming.

Quiet expansion moves

Nu has been a successful disruptor in its home turf, Latin America. But as it proves itself in its turf, it is now setting its sights on new opportunities beyond its core markets.

Two moves look particularly exciting. One, it made a $150 million investment to buy a 10% stake in Tyme Group, a South African fintech company. Founded in 2019, Tyme Group operates a hybrid digital banking model that combines online banking with physical service touchpoints, serving 15 million customers across South Africa and the Philippines.

The investment in Tyme Group demonstrates Nu's ambition of expanding beyond its home markets. Although currently small, the 10% stake in Tyme could serve as a springboard for future investments in this region.

Besides, Nu is considering moving its domicile to the U.K. and also expanding into the U.S. While still early days, these moves could lead to new opportunities, access to global talent and global capital markets, positioning the company well for the next decade of growth.

These aren't splashy headlines. But they're deliberate steps in a long-term strategy: expand cautiously, deepen profit pools at home, and gradually position for global scale.

What does this mean for investors?

Nu has moved past the stage of proving it can grow. The question now is how far it can extend its empire. To this end, it's improving profitability, increasing customer monetization, and slowly exploring market expansions.

If it continues executing, Nu has a chance to become not just a fintech success story, but a dominant bank of Latin America -- with optionality to go even further. Growth investors should keep the company on their watchlist.