The bond market (also debt market or credit market) is a financial market where participants can issue new debt, known as the primary market, or buy and sell debt securities, known as the secondary market. This is usually in the form of bonds, but it may include notes, bills, and so for public and private expenditures. The bond market has largely been dominated by the United States, which accounts for about 39% of the market. As of 2017, the size of the worldwide bond market (total debt outstanding) is estimated at $100.13 trillion, according to Securities Industry and Financial Markets Association