Bonds, Interest Rates, and the Impact of Inflation

There are two fundamental ways that you can profit from owning bonds: from the interest that bonds pay, or from any increase in the bond's price. Many people who invest in bonds because they want a steady stream of income are surprised to learn that bond prices can fluctuate, just as they do with any security traded in the secondary market. If you sell a bond before its maturity date, you may get more than its face value; you could also receive less if you must sell when bond prices are down. The closer the bond is to its maturity date, the closer to its face value the price is likely to be.

Though the ups and downs of the bond market are not usually as dramatic as the movements of the stock market, they can still have a significant impact on your overall return. If you're considering investing in bonds, either directly or through a mutual fund or exchange-traded fund, it's important to understand how bonds behave and what can affect your investment in them.

Just as a bond's price can fluctuate, so can its yield--its overall percentage rate of return on your investment at any given time. A typical bond's coupon rate--the annual interest rate it pays--is fixed. However, the yield isn't, because the yield percentage depends not only on a bond's coupon rate but also on changes in its price.

Both bond prices and yields go up and down, but there's an important rule to remember about the relationship between the two: They move in opposite directions, much like a seesaw. When a bond's price goes up, its yield goes down, even though the coupon rate hasn't changed. The opposite is true as well: When a bond's price drops, its yield goes up.

That's true not only for individual bonds but also the bond market as a whole. When bond prices rise, yields in general fall, and vice versa.