Microsoft, founded in 1975 by Bill Gates and Paul Allen, later joined the trillion-dollar market-cap club.
Microsoft was incorporated on April 4, 1975, after Gates and Allen developed software for the Altair 8800 microcomputer. The company’s early success came from licensing Microsoft BASIC, followed by the MS-DOS operating system and the Windows family.
Microsoft’s market capitalization first exceeded US$1 trillion in April 2019. Its later valuation growth was supported by businesses including Windows, Office, Azure, Xbox, LinkedIn, and enterprise software. Azure became especially important as cloud computing expanded.
A market-cap milestone does not mean the company earned that amount in profit or possessed that amount in cash. It represents the stock market’s value for all outstanding Microsoft shares at a particular share price.