Of course, it's Bill Gates, provided his monopolistic heart keeps beating for another 20 years or so. In fact, in the most optimistic of the four scenarios below - which assumes Microsoft shares continue to rise at their historic, nothin'-but-blue-sky rates - Gates will become a trillionaire just five years from now, and a quadrillionaire (1,000 trillion) before he hits retirement age.
To grasp that staggering figure, consider that to spend a quadrillion, you'd have to blow $1 million a day for 3 million years - or a period 100 times longer than recorded human history.
Age 49
The value of Bill's Microsoft stake has grown from $233.9 million at the time of Microsoft's 1986 IPO to $72.2 billion as of June 15, 1999 (disregarding stock sales). At this rate - 58.2 percent a year - he will become a trillionaire in March 2005, at age 49, and his Microsoft holdings will be valued at $1 quadrillion in March 2020, when he is 64.
Age 59
If Microsoft can't maintain its remarkable returns, but the value of Mr. Softie grows annually at the same rate - 17.6 percent - that the S&P 500 has averaged over the last 20 years, poor Bill would have to wait until he was 59, in August 2015, before he becomes a trillionaire. He wouldn't become a quadrillionaire until March 2058, at age 102.
Age 61
Say Bill decides to diversify. He sells all his Microsoft stock (to simplify things, let's assume this doesn't tank the stock), pays his 20 percent long-term capital gains tax, and stuffs the remainder in a mutual fund that tracks the S&P. Even after paying the tax man, Bill would still hit trillionairehood in January 2017, at 61, and age into a 103-year-old quadrillionaire.
Age 111
Bill no longer believes in the stock market. He sells all his Microsoft stock, pays the IRS, and buys $57.7 billion worth of Series EE US Savings Bonds. Even playing it that safe, Bill's net worth would top $1 trillion in January 2067, when he's 111. At this rate, Bill would likely be in cryonic deep freeze in September 2230, when he'd reach quadrillionairehood.
