The U.S. government currently issues new Treasury notes and bonds with maturities in 2, 3, 5, 10, and 30 years. The 30 year bond is called the long bond, and it is considered one of the benchmark indicators of interest rates.
A bond maturing in 10 or more years. Because an investor's money is tied up for a long time, the bonds are riskier than shorter term bonds of the same quality. Thus, they usually pay a higher yield. See: Bond; Long Term Debt; Maturity Date; Risk/Reward Ratio; Short Term Debt; Yield