Bill Gates has been the richest man in the world for 15 out of the past 20 years. Even though he's given an astounding $38 billion to his charitable foundation, he keeps getting richer every year.
As of March 2014, Gates is worth $76 billion, according to Forbes' annual list of billionaires. That's $9 billion more than a year ago and $4 billion more than six months ago.
His net worth has been helped by an uptick in Microsoft's share price (up by about $10 a share since last March), but Microsoft isn't the source of most of his money, and hasn't been for a while. Microsoft accounts for less than one-fifth of his total net worth, according to Bloomberg's Billionaire Index.
Most of his wealth comes from his investment company, Cascade Investment. It owns stakes in Canadian National Railway, Berkshire Hathaway, Deere & Co., Liberty Global, Waste Management, and other firms, according to forms filed with the Securities and Exchange Commission.
Over the past 10 years, Gates has sold off a large chunk of his Microsoft stake, about 80 million shares, reports Computerworld's Gregg Keizer. Specifically, in September 2004, Gates had 1.1 billion shares of Microsoft. As of his last trades in February, he owned 337,991,164 shares, according to Yahoo's Insider Trading site (based on forms filed with the SEC).
He still owns more than a 4 percent stake of Microsoft and is still the company's single largest shareholder, according to Bloomberg. But if Gates continues to sell Microsoft shares at the same rate and doesn't acquire more, by 2015 for the first time in the company's history, that could change. Steve Ballmer could become the company's largest stakeholder.
In 2013, Gates sold 43,000,000 shares of Microsoft (although he also acquired a few, 5,554), according to Insider Trading records. Ballmer currently holds 333,252,990 shares now, according to SEC forms, and hasn't sold any in years. That's just 47,38,174 shares fewer than Gates.