Most investors care about future interest rates, but none more than bondholders. If you are considering a bond or bond fund investment, you must ask yourself whether you think interest rates will rise in the future. If the answer is yes then you probably want to avoid long-term maturity bonds or at least shorten the average duration of your bond holdings; or plan to weather the ensuing price decline by holding your bonds and collecting the par value at maturity. (For a review of the relationships between prevailing interest rates and yield, duration, and other bond aspects, please see the tutorial Advanced Bonds Concepts .)

The Treasury Yield Curve

In the United States, the Treasury yield curve (or term structure ) is the first mover of all domestic interest rates and an influential factor in setting global rates. Interest rates on all other domestic bond categories rise and fall with Treasuries. which are the debt securities issued by the U.S. government. To attract investors, any bond or debt security that contains greater risk than that of a similar Treasury bond must offer a higher yield. For example, the 30-year mortgage rate historically runs 1% to 2% above the yield on 30-year Treasury bonds.

Below is a graph of the actual Treasury yield curve as of December 5, 2003. It is considered normal because it slopes upward with a concave shape:

Consider three elements of this curve. First, it shows nominal interest rates. Inflation will erode the value of future coupon dollars and principal repayments; the real interest rate is the return after deducting inflation. The curve therefore combines anticipated inflation and real interest rates. Second, the Federal Reserve directly manipulates only the short-term interest rate at the very start of the curve. The Fed has three policy tools, but its biggest hammer is the federal funds rate. which is only a one-day, overnight rate. Third, the rest of the curve is determined by supply and demand in an auction process.

Sophisticated institutional buyers have their yield requirements which, along with their appetite for government bonds, determine how these institutional buyers bid for government bonds. Because these buyers have informed opinions on inflation and interest rates, many consider the yield curve to be a crystal ball that already offers the best available prediction of future interest rates. If you believe that, you also assume that only unanticipated events (for example, an unanticipated increase in inflation) will shift the yield curve up or down.

The following chart compares the 10-year Treasury yield (red line) to the one-year Treasury yield (green line) from June 1976 to December 2003. The spread between the two rates (blue line) is a simple measure of steepness: