The world's richest people are on a constant lookout for ventures that are reshaping the world, and they're usually going for startups before they go public. If investors get in on the early stages of companies, they can have more influence and boost their value by drawing media attention to them. Investing in early-to-mid-stage startups that eventually reach an initial public offering (IPO) or are acquired by a bigger company tends to reel in returns that most investors don't see in their entir