Microsoft became the first company to reach a $500 billion market capitalization in 1999.
Microsoft crossed the half-trillion-dollar valuation during the technology boom of the late 1990s. Investors placed a high value on the company’s dominant Windows operating system, Office software, and growing position in personal-computer technology.
The milestone occurred before today’s largest technology firms reached trillion-dollar valuations. Microsoft’s stock later suffered during the dot-com crash, showing that a record market capitalization is not a permanent measure of corporate strength.
Microsoft was founded by Bill Gates and Paul Allen in 1975. Its business later expanded beyond packaged PC software into cloud computing, enterprise services, gaming, and professional networking. The company’s long-term valuation story is therefore broader than its original role in desktop computing.