Our focus thus far has been on the shape of the Treasury yield curve. In fact, often the financial press in its discussion of interest rates focuses on the Treasury yield curve. However, as explained in Chapter 5, it is the default-free spot rate curve as represented by the Treasury spot rate curve that is used in valuing fixed-income securities. But how does one obtain the default-free spot rate curve? This curve can be constructed from the yields on Treasury securities. The Treasury issues that are candidates for inclusion are: