Microsoft was founded in 1975 by Bill Gates and Paul Allen and later became one of the first companies to reach a $1 trillion market capitalization. Its shares passed that threshold in April 2019, after Apple and Amazon had already achieved it.
Microsoft initially became famous for software used on personal computers. MS-DOS and Windows helped establish its dominance in operating systems, while Microsoft Office became a standard productivity suite for homes, schools, and businesses. The company later expanded into enterprise software, cloud computing, gaming, search, and hardware.
Azure cloud services became a major growth engine and helped reposition Microsoft as a cloud platform company. Microsoft also owns Xbox and acquired LinkedIn in 2016. These businesses give the company revenue beyond its traditional desktop-software roots.
Microsoft’s market capitalization reflects the value investors place on the entire corporation, not just Windows. Like other mega-cap companies, its precise ranking changes with share prices, earnings expectations, and broader market conditions.