Facebook was the first company founded in the 21st century to reach a US$1 trillion market capitalization.
Facebook was founded in February 2004 and passed the US$1 trillion market-capitalization threshold in June 2021. That made it an unusually young company to join the group of publicly traded corporations valued at a trillion dollars or more.
Facebook’s rapid growth came from scaling a global social network and building a large advertising business around user engagement and data-driven targeting. It also expanded through acquisitions, including Instagram in 2012 and WhatsApp in 2014. Those services helped broaden the company’s reach beyond its original website.
This question concerns the company’s founding date and valuation, not the date of its stock-market debut. Facebook became publicly traded in 2012, eight years after its founding. In October 2021, its corporate parent changed its name to Meta Platforms, although the social network itself continued to be called Facebook.