Warren Buffett is often quoted as saying his favorite holding period is "forever." But there are only a handful of companies in Berkshire Hathaway's (NYSE: BRK.A) (NYSE: BRK.B) equity portfolio that he truly plans to hold indefinitely.

Buffett is a long-term value investor who often holds stocks for decades, so you won't find him chasing the latest market trends, not even those as powerful as artificial intelligence (AI). However, at least three existing holdings in Berkshire's portfolio are using AI to enhance their legacy businesses.

Warren Buffett, the legendary investor and chairman of Berkshire Hathaway, has built a reputation for long-term, strategic investing. While Berkshire is best known for its stakes in Apple,