The SpaceX IPO is here, and it’s more than just an historic public offering that could make Elon Musk the world’s first trillionaire. It also reveals more ways in which Elon Musk’s companies interact and overlap with each other, shuffling money around in ways that are often difficult to keep track of. In SpaceX’s IPO, Elon Musk is a risk factor The rocket company says it’s ‘highly dependent’ on Mu...