The US bond market is the largest debt securities market in the world, with more than $50 trillion in outstanding bonds. It includes bonds issued by the US Treasury (the safest assets), government agencies, corporations (both investment-grade and high-yield), municipalities (tax-exempt), and mortgage-backed securities. Treasury bonds set the global benchmark for risk-free interest rates and heavily influence mortgage rates and overall borrowing costs. Unlike stocks, bonds are traded over-the-counter rather than on a centralized exchange, and the bond market is significantly larger and more liquid than the US stock market.