Microsoft became the first publicly traded company valued at $500 billion.
Microsoft reached the milestone during the technology boom in 1999, when enthusiasm for personal computers and software pushed its share price sharply higher. The company’s Windows operating system and Office productivity suite were central to its dominance in desktop computing.
The achievement came before the later trillion-dollar era, when Apple, Amazon, Microsoft, and Alphabet reached far larger valuations. Microsoft’s market value subsequently fell during the dot-com crash, showing that a record valuation is not permanent.
Microsoft was founded in 1975 by Bill Gates and Paul Allen. Its modern business also includes Azure cloud computing, enterprise software, gaming, and professional networking through LinkedIn.