An upbeat look at how getting in early on Elon Musk's companies made a few insiders enormously rich.

• A friend who put $1 million into SpaceX early owned 7.3% of the company.
• When SpaceX goes public, that stake could be worth around $100 billion.
• The takeaway: backing a winning founder early, and sticking around, can turn a small bet into a fortune.
• Musk pulled the people around him up with him, creating wealth across his inner circle.

Outlook: A SpaceX public listing would turn these paper gains into real money, making early backers among the biggest winners.