Alphabet stock jumps after Berkshire adds new $4.3B stake

Core Insights - Shares of Alphabet Inc. experienced a significant increase in premarket trading following Berkshire Hathaway Inc.'s announcement of a substantial new investment in the company, marking a notable addition to its portfolio in Q3 2025 [1] Company Summary - Berkshire Hathaway acquired 17.8 million Class A shares of Alphabet, which are valued at $4 billion [1]