The Amazon founder's wealth rocketed to $105.1 billion, according to the Bloomberg Billionaires Index, after shares in the company soared on strong holiday sales. The record was previously held by Microsoft founder Bill Gates, whose net worth was briefly above $100 billion in 1999. (And he'd still top the chart if he hadn’t given so much of his wealth to charity.) But if you account for inflation, Bezos has competition; Augustus Caesar's fortune, for example, could be worth a cool $5 trillion. Either way, the Amazon chief is worth more than the GDP of 125 of the world’s 195 countries.