Gary Poster, with essential assists from Galyn Norwood, Phiroon Phihakendr, Jose Quijada, Pavandeep Kalra.
Most people think a market crash is the biggest danger to investors.
Finally, let's say the market takes a 30 percent dive over the next year. Every time you check your stocks or stock mutual funds, you're going to feel the pain. Likewise, if interest rates rise, your bonds won't let you forget it. Factor in inflation, which has historically run at about 3.1 percent annually, and it will take closer to ten years to double your actual buying power. After inflation, however, it will take 35 years.