Microsoft held the world's largest market capitalization at the end of 1999 during the dot-com era.
Microsoft reached the top of global market capitalization rankings during the late-1990s technology boom. Its dominant Windows operating system and Office productivity software produced substantial profits, while investors placed high expectations on internet and personal-computer growth.
The company was founded by Bill Gates and Paul Allen in 1975 and became a public company in 1986. Its market value later fell during the dot-com crash, but Microsoft rebuilt growth through businesses including server software, Azure cloud computing, enterprise subscriptions, gaming, and professional networking.
Rankings can vary with the exact trading date and whether a source uses closing or intraday prices. The 1999 milestone belongs to Microsoft's position at the end of that year, not to a claim that it remained number one throughout the entire technology boom.