What ChatGPT, Google Gemini and Microsoft Copilot think is 'mystery stock' of Warren Buffet, the world's biggest investor

The world's biggest investor Warren Buffett has a secret. In recent quarters, Warren Buffet's Berkshire Hathaway’s 13F reportedly has hinted at a position it’s building under confidential treatment. According to a report, clues in the company’s 10Q filings point many observers to an industrial name, with the stake approaching $5 billion. To find out the mystery stock valuing almost $5 billion, CNBC decided to ask the question to some of the popular AI chatbots, including ChatGPT, Google Gemini and Microsoft co-Pilot.The prompt used: For the past few quarters, Berkshire Hathaway’s 13F filings have disclosed a confidential holding. Using only information from Berkshire’s own filings (13Fs, 10Qs, 10Ks, etc.) and your knowledge of Warren Buffett’s investment strategy, make a strong, specific and well-reasoned guess as to what that holding is. Ignore speculation from market participants and news articles.As per CNBC report, ChatGPT thinks that the secret holding is GE Aerospace. It is reported to have picked up on that jump in Berkshire’s cost basis in the commercial and industrial space during the first half of the year. ChatGPT pointed to GE’s wide moat from its installed base and its long-duration cash flows, which are characteristics that fit a value investor’s taste: “Buffett loves durable, toll-like economics,” it wrote. ChatGPT called its confidence “moderate” and offered Deere and UPS as runner-up picks. The OpenAI's chatbot also reportedly ruled out financials, pointing out that while the cost basis for industrials rose, it fell for the financial bucket.Microsoft’s Copilot picked Visa. Copilot reasoned that Visa reinforces its moat with each transaction, generates recurring cash flows and routinely posts around 30% return on equity. The report added, "Interestingly, Copilot also claimed there’s “no public 13F line for Visa” even though it appears in Berkshire’s latest filing." Google Gemini focused on transportation. It said that the trail points to logistics and freight rail. As per the report, "It leaned on classic Buffett filters: wide moats, essential infrastructure, predictable cash flows and straightforward models as the reason to favor rails over other industrials. Gemini’s specific guesses: Union Pacific or CSX . Both, it argued, are long-duration compounding machines that Berkshire would plausibly accumulate quietly."