Warren Buffett Has a New Favorite Quantum Computing Stock. (Hint: It's Not D-Wave or IonQ.)

Core Insights - Warren Buffett is preparing to step down from Berkshire Hathaway but has identified a new favorite in quantum computing stocks, which is Alphabet, not D-Wave Quantum or IonQ [1][5] - Prior to Q3 2025, Amazon was the only quantum computing stock in Berkshire's portfolio, but the conglomerate has now invested significantly in Alphabet [3][5] Company Investments - Berkshire Hathaway purchased over 17.8 million Class A shares of Alphabet, valued at more than $5 billion, which is more than double its investment in Amazon [5] - Alphabet's Google Quantum AI is a leader in quantum computing, having achieved significant milestones, including a calculation that would take supercomputers 10,000 years to complete in just 200 seconds [6] Business Focus - The investment in Alphabet is likely driven more by its robust advertising business rather than its quantum computing initiatives, as evidenced by the $74.2 billion revenue generated from advertising in Q3 2025 [8][9]