Which bonds are the only federal government security traded on the primary market?

Treasury bonds are indeed the only federal government securities traded on the primary market. When the U.S. Treasury issues these bonds, they are sold directly to investors through auctions. This process allows the government to raise funds needed for various public expenditures, including financing the national debt and funding government programs.

Treasury bonds are characterized by their long maturities, typically ranging from 10 to 30 years, and they pay a fixed interest rate over that duration. Unlike other types of bonds mentioned, such as corporate bonds, savings bonds, and muni bonds, which are issued by private corporations, states, or municipalities, Treasury bonds are specifically backed by the full faith and credit of the U.S. government.

This backing gives Treasury bonds a high level of safety and stability, making them a fundamental component of many investors' portfolios. Hence, the unique nature of Treasury bonds as federally issued securities that are issued and traded in the primary market sets them apart from other types of bonds.