Core Insights - Alphabet's stock price increased by 5.2% in pre-market trading following the disclosure that Berkshire Hathaway, led by Warren Buffett, has built a position in Alphabet [1] - As of September 30, Berkshire holds 17.85 million shares of Alphabet, valued at approximately $4.93 billion based on recent closing prices [1] - This investment marks a rare move by Buffett into the technology sector, amidst growing concerns over significant expenditures by tech giants in AI and data center infrastructure [1] Company Summary - Berkshire Hathaway's investment in Alphabet is seen as one of the last major investments under Buffett's leadership, who will step down as CEO by the end of 2025 [1] - The market is increasingly worried about the substantial capital being allocated by tech companies for data centers and chip acquisitions, amounting to hundreds of billions of dollars [1] Stock Performance - As of the report, Alphabet's stock price rose by 4.91% [1]