Nu Holdings extends four-day gain to 36% after Warren Buffett's Berkshire Hathaway reveals $1 billion stake in the Brazilian bank

• Warren Buffett's Berkshire Hathaway revealed a $1 billion stake in Nu Holdings.
• The Brazilian bank has soared 36% since the stake was revealed in a 13F filing earlier this week.
• Nu Holdings went public late last year and was founded in 2013 as a digitally focused financial services company.

Nu Holdings extended its week-long gains to as much as 36% on Friday as the Brazilian bank starts to receive some love from American investors following its late-2021 IPO.

Warren Buffett's Berkshire Hathaway is one of those investors. The company began buying shares of Nu Holdings last quarter, according to its most recent 13F filed with the SEC on Monday.

The $1 billion stake initiated in Nu Holdings by Berkshire Hathaway highlights the conglomerates' still-strong market moving abilities, and the fact that investors still closely follow the moves made by the "Oracle of Omaha."

Granted, there is no indication that Warren Buffett himself initiated the purchase of Nu Holdings, or if one of his portfolio management lieutenants bought the stock, which is current as of December 31.

Berkshire purchased 107.1 million shares of Nu Holdings at an estimated average price of $9.38 per share. The stock hit a high of $11.83 in Friday trades.

Another high profile investment firm that initiated a stake in the Brazilian bank is Tiger Global Management, which purchased 266.0 million shares last quarter worth $2.5 billion, making it the firm's fourth largest position behind JD.com, Microsoft, and Sea Limited.

While the buyside is eating up shares of Nu Holdings, some sell-side analysts are also excited about the stock and recommending it to investors. Goldman Sachs initiated the Latin American fintech company with a "Buy" rating and a $15 price target, representing potential upside of 28% from current levels.

"As the largest digital banking platform outside of Asia with 48 million clients, we think Nubank is well positioned to penetrate the highly profitable banking system in Latin America, particularly in Brazil, Mexico and Colombia where it currently has operations," Goldman said in a note last month.