Core Insights - Berkshire Hathaway has acquired 17,846,142 shares of a prominent AI stock, valued at $4.3 billion, making it one of its top 10 holdings by value [1][2] - This marks a significant shift in Warren Buffett's investment strategy, as he has historically avoided AI stocks [1][2] - The recent purchase of Alphabet (Google's parent company) suggests a growing bullish sentiment towards AI within Berkshire Hathaway [8][11] Company Holdings - Berkshire's largest position remains in Apple, valued at over $60 billion, despite a previous peak of over $200 billion [4] - Berkshire has also held a multibillion-dollar position in Amazon since Q1 2019, with Amazon Web Services (AWS) being a key player in AI infrastructure [5] - The recent acquisition of Alphabet stock indicates that Berkshire now has three major companies with direct ties to AI: Apple, Amazon, and Alphabet [11] Investment Strategy - The decision to invest in AI stocks may not have been solely made by Buffett, as portfolio managers Todd Combs and Ted Weschler have been instrumental in previous significant purchases [6][9] - Buffett has expressed regret for not investing in Alphabet earlier, indicating a potential shift in his investment philosophy towards technology and AI [9][10]