Net Worth: $56 billion UP
Microsoft mogul, futurist and America's richest person has, with help from billionaire buddy Warren Buffett, convinced nearly 60 of the world's wealthiest to sign his "Giving Pledge," promising to donate the majority of their wealth to charity either during their lifetime or after death. He is no longer the planet's richest person, but that's because he's given away $30 billion to his foundation. The Gates Foundation, the world's most influential charity, tackles tuberculosis and polio and funds famine-resistant crops to fight hunger. He is calling for a higher sense of urgency in AIDS vaccine development and also pushing for better tools to rate teacher performance. Gates holds 70% of his wealth in investment fund Cascade, dabbling in everything from autos to hedge funds to Mexican Coke bottler Femsa; the rest of his wealth is held in Microsoft stock.
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