I'm a retiree who spend almost 30 years in the retirement industry. What most people fail to realize is that if you and your spouse both retire this year at age 65, there's a 49% probability that one of you will live to age 95. That's 30 years of inflation eating away at the purchasing power of your fixed income investments such as bonds. With 10 year treasuries yielding only 2.23% interest and inflation running at 1.7%, you are actually making only .53% on your money in real dollars. If inflation reaches even 2.5%, you are going backward.

People also don't appreciate that the value of the pricipal of bonds declines if interest rates rise. With interest rates near historic lows, the chance of the value of your bonds being lower than your purchase price, if you have to sell them to raise cash for an emergency, is very large.

Certainly you need a rainy day cash reserve equal to about 6 months of living expenses. But beyond that, particularly in the curent environment of low interest rates, you should be primarily in conservative large-cap stocks that pay dividends and increase those dividends each year to maintain your purchasing power.