So SpaceX is disrupting: Satellite development, Rocket development, Rocket launch and services, Internet service infrastructure, and now long distance Earth transport. On top of that they're creating entirely new sectors with tourism/research on the moon and colonization/exploration of Mars.
If a company focused on any individual one of these fields and had any measure of success they'd be a multi-billion dollar company, with SpaceX doing all of them I fully expect them to be a multi-trillion dollar company; and Elon Musk owns over 50% of it.