Note: I've revised the charts for this article, shifting the annualized returns to the left so that the return value lines up with the year the lump-sum investment is made. The original version showed the return at the end of the investment period, which some readers found confusing.

Here's a sobering set of charts that will especially resonate with those of us who follow economic cycles.

Imagine that ten years ago you made a single, lump-sum investment in the S&P 500. How much would it be worth today, adjusted for inflation with dividends reinvested? Brace yourself: Your investment lost 44.7% for an annualized return of minus 5.9%.

Now let's imagine that we time-travel back to September 2000 and pose the same question. Your ten-year inflation-adjusted gain would have been 396% for an annualized return of 16.13%. As the chart illustrates, investment performance with a 10-year timeline has been a real roller coaster as far back as we have data.

If we extend our investment horizon to 20 years, the roller coaster is less volatile with higher lows and lower highs. The volatility decreases further with a 30-year timeline. But even for that three-decade investment, the annualized returns since the 1901 have ranged from less than 2% to over 11%.

As these charts illustrate, and as many households have discovered over the past 18 months, investing in equities carries risk. Households approaching retirement should understand this risk and make rational decisions about fixed income alternatives for that part of the nest egg that will pay non-discretionary expenses not covered by Social Security and pensions.