Microsoft was the first company to surpass a $500 billion market capitalization during the dot-com era.
Microsoft crossed the $500 billion market-value threshold in 1998, during the rapid expansion of technology stocks. Its dominant Windows operating system and Office productivity software produced powerful profits and made the company a central symbol of the personal-computer boom.
The milestone came before the larger trillion-dollar valuations reached by technology companies decades later. Microsoft’s market value subsequently rose and fell with the technology bubble, competition concerns, and changes in the software industry. The company remained a major public company even after the dot-com bubble burst.
Market capitalization is based on shares outstanding multiplied by the current share price. Historical comparisons can be complicated by stock splits, which alter the quoted share price without changing the company’s total value. Microsoft has completed several stock splits, including a two-for-one split in 1998.