Alphabet shares surged to a record high on Monday, climbing nearly 6% after Berkshire Hathaway disclosed a new multibillion-dollar stake in the Google parent company. The purchase, totaling 17.85 million shares valued at approximately $4.9 billion, marks one of Berkshire’s final large investments under Warren Buffett’s leadership — and a notable shift for a conglomerate traditionally cautious about high-growth tech stocks.