Zoom out. Even after Friday's drop, Nu has soared 69% this year. Go back further, and you'll see the stock has soared 245% since the start of last year. Buffett owns 20.7 million fewer shares now, but the value of his Nu stake is 56% higher than it was at start of this year and a beefy 197% greater than it was a year earlier.

Despite his immense wealth, Warren Buffett, as he admits, is a man of simple tastes. Perhaps that focus on basic American food staples inspired one of the more unexpected new buys from his investment vehicle Berkshire Hathaway (NYSE: BRK.

Berkshire bought 1.28 million shares of the global pizza delivery chain, which were valued at $550 million at the end of the third quarter. And he added more than 400,000 shares of the wholesale distributor of pool equipment. Shares of both companies jumped on news of Buffett's investments.