Berkshire sold 20.7 million of those shares in the third quarter of 2024, but its 86.4 million remaining shares are still worth $949 million and give it a 1.8% stake in the company. Berkshire's stake in Nu only accounts for 0.3% of its entire portfolio, but the Latin American bank is still growing much faster than its brick-and-mortar competitors.

Warren Buffett primarily buys large-cap stocks for Berkshire Hathaway's portfolio. Because of this focus on large-cap stocks, you probably won't be surprised that Buffett owns six stocks that are members of the Dow Jones Industrial Average (DJINDICES: ^DJI).

The third industry-leading AI stock Warren Buffett secretly owns shares of via New England Asset Management is Alphabet (NASDAQ: GOOGL)(NASDAQ: GOOG). Despite NEAM selling shares of Alphabet for five consecutive quarters, the fund still held 5,195 Class A shares (GOOGL) as of Sept. 30.

Berkshire Hathaway CEO Warren Buffett was born in Omaha, Nebraska, in 1930 and is one of history's most successful investors. Trained under the tutelage of Benjamin Graham, the father of value investing,