NVIDIA maintains its leading 68.5% implied probability to finish as the largest company by market cap at the end of December 2026, driven by sustained demand for its AI-optimized GPUs and data-center revenue growth that has propelled its valuation above $5 trillion. Alphabet’s 21.0% odds reflect recent momentum from 63% year-over-year Google Cloud expansion and Q1 2026 earnings beats that narrowed the market-cap gap to roughly $200–400 billion. Apple’s 7.1% chance rests on stable services revenue and device sales, while lower-probability names such as SpaceX, Saudi Aramco, and Microsoft trail due to slower recent share-price appreciation relative to the top two. Traders are pricing in continued AI capital spending through year-end as the decisive factor.