Which social-media company first reached a US$1 trillion market capitalization?

Meta Platforms first reached a US$1 trillion market capitalization in June 2021.

The company crossed the threshold on 28 June 2021, when its shares rose to a level that valued the business at more than US$1 trillion. At the time, the company was still named Facebook, Inc.; it changed its corporate name to Meta Platforms in October 2021. The Facebook social network remained its best-known product, alongside Instagram, Messenger, and WhatsApp.

Meta’s valuation was powered by a huge advertising business built around user engagement and targeted digital marketing. Its later rebranding signaled a strategic focus on the metaverse, virtual reality, and augmented reality, although those activities represented only part of the company’s overall business.

The answer is sometimes given as “Facebook,” which was the company’s name when it crossed the milestone. “Meta Platforms” is the current corporate name and the canonical answer for the company itself.