Microsoft overtook Apple as the world's most valuable publicly traded company in January 2024, before Nvidia later took the lead.
Microsoft's market capitalization benefited from investor enthusiasm for cloud computing and artificial intelligence. Its partnership with OpenAI, Azure's data-center business, and AI features added to expectations that Microsoft could expand its already large software operations.
The change in ranking was not caused by Microsoft buying Apple or by Apple disappearing from the top tier. It resulted from the relative movement of the two companies' share prices and their outstanding shares. Microsoft and Apple traded the top position more than once during the period.
Nvidia's later rise showed how quickly market-cap leadership can change. Rankings are useful snapshots of investor valuation, but they do not necessarily identify the company with the highest sales, profits, assets, or employee count.