When it comes to billionaire investors, Bill Gates is pretty much a household name. He made his fortune as the CEO of Microsoft (NASDAQ: MSFT), the software company he co-founded. Gates is worth an estimated $127.7 billion (as of this writing), according to Forbes, making him the world's eighth richest person world. As a result of the regular inflows of Gates's wealth, dividend payments, and outflows to charitable ventures, the trust's stock holdings and the amounts change regularly. While the portfolio has stakes in two dozen companies in all, the vast majority is held in just four stocks.