Nu Holdings (NU -2.72%) has been an incredible stock to own over the past few years, and it's no surprise that several billionaire fund managers own it. What might be surprising is the breadth of investors who have scooped it up. It appeals to both Warren Buffett and Cathie Wood, two investors whose investing styles are as like night and day, and whose only other stock in common is Amazon.

But is its growth streak over? Buffett's Berkshire Hathaway just sold 19% of its stake in Nu, or more than 20 million shares. It now accounts for just 0.4% of the total Berkshire Hathaway portfolio. Famed investment manager Israel Englander of Millennium Management sold shares as well, and nearly his entire position -- 99%.

Do they know something the market doesn't know? I don't think so. I'll explain why I think they sold and why Nu is still a top stock for many investors, and I'll also tell you which billionaire managers just took a position in Nu.

What's happening at Nu

Nu stock has had an incredible run, and it's up more than 200% over the past two years. It has a disruptive digital business in its online financial services, and it's shaking up the traditional banking system in its headquarters of Brazil.

Although it demonstrated strong results in the 2024 third quarter, they were a bit of a slowdown from previous quarters. Revenue increased 56% on a currency-neutral basis, and net income more than doubled to $553 million. Average revenue per active customer (ARPAC) increased 25% year over year on a currency-neutral basis, but was down sequentially over the past two quarters on a reported basis. Net interest income increased 63% over last year, but net interest margin narrowed year over year and sequentially.

It added 5.2 million members for a total of 109.7 million. It has continued momentum in Brazil, where 1.1 million new members joined the platform each month, and it added 1.2 million members in Mexico for a total of 8.9 million. It also surpassed 2 million in Colombia. It was a good quarter objectively, but the market is never objective. The market also factors in valuation, so whereas it could carry a higher valuation with astronomical increases, it can't carry the same premium with lower increases.

Another reason the market is concerned is that Brazil just hiked interest rates again. Unlike in the U.S., where inflation seems to be cooling and the Federal Reserve is cutting interest rates, inflation is still rampant in Brazil, and interest rates were just hiked again. There's worry about how that will impact Nu's business as a bank in the near term.

But investors shouldn't misunderstand; business is booming and it has a massive opportunity.

Why some billionaires sold

Nu is far from the typical Buffett stock. It a young fintech stock, and it has grown at a much faster pace than the typical Buffett stock recently. While the average investor might find that delightful, there are at least two reasons that could be why Buffett cut his position. One is that Nu has always been meant to be a small piece. It's not a typical Buffett bet, and now that it's ballooned in size, it might be accounting for more than Buffett wants to allot for this kind of stock.

Combined with that, Brazil is experiencing more economic volatility lately, and Buffett likely wants to limit his exposure to volatile foreign economies.

Englander likely has a different reason for selling. Nu stock was on a tear before it fell after the third-quarter report, which was after Millennium's sale. Millennium owns thousands of stocks and has a serious and sophisticated investing model that includes puts and calls. After Nu's incredible run-up, he might have felt that some correction was coming and didn't want to have a large position when that happened. But he also didn't completely pull out, because the potential is so strong.

These are the billionaires who bought

There's rarely a consensus about whether or not to buy a stock at any given time, and even if there is, some of the most successful billionaire investors got where they are by being the contrarian. Every manager has their own style and investing method, and they're almost always going to be different from the average investor's.

Consider that two other highly successful billionaire investors opened new positions in Nu stock in the third quarter. Ken Fisher of Fisher Asset Management bought more than 7 million shares, and Paul Tudor Jones of Tudor Investments took a smaller position with 100,000 shares.

What should investors do? If you have a long time horizon and are looking for a great growth stock, you can buy Nu stock right now. There may be some short-term pressure, and you should never expect linear gains. Nu didn't plummet, because the investment thesis is strong. You can view the drop as an opportunity to buy on the dip.