He already has to some extent. But how do you put a monetary value on that? Well, you could start with an Elon Musk ETF. Although this is hypothetical of course, you, as an Elon Musk shareholder, could have made very profitable returns, many times over at this point. I'm basically talking about PayPal (now part of eBay ( EBAY), Tesla Motors ( TSLA) and SolarCity ( SCTY), because SpaceX and the pending Hyperloop are not open to public investment. What if you had invested $10,000 in each company during the first day of trading? The results would be staggering. PayPal went public in February 2002. The company floated 5.4 million shares and opened at $15.41, before settling at a bit more than $20 a share. Assume you got in somewhere in the middle, say $17. Your $10,000 would have bought you about 588 shares. A few months later, eBay ( EBAY) announced it would acquire PayPal for $1.5 billion in stock, swapping 0.39 shares of its own stock, for each PayPal share. This worked out to each share of PayPal equaling about $23.61, a 38% gain from your $17 entry point. But, assuming you didn't sell your 229 shares of eBay (588 shares of PayPal, times 0.39 shares of eBay = 229 total shares of eBay), you'd be sitting on more than 900 shares today. After a 2-for-1 stock split in 2003, followed by another in 2005, you'd have 916 shares, each valued at approximately $54. Your total investment would be worth $49,464, nearly a 500% gain on your $10,000 investment. Fast forward to June 2010, when Tesla made its public debut. The stock opened at $19 per share and closed at $24.62. Again, based on a rough estimate, let's assume you bought the stock at $22, which amounts to about 454 shares on a $10,000 investment. Tesla started off 2013 at $35 per share, a modest 60% return on the invested capital in less than two years. But the ride's just getting started. Musk and the company continued to wow Wall Street with its highly touted Model S. The car scored a 99 out of 100 from Consumer Reports, the publication's highest rating for a car, ever.