A bond is a trade-able financial instrument. A company or government can issue bonds to raise money from investors. The investor in turn earns an interest on the investment and the principal on maturity. Simply put, bonds are a receipt for a loan taken by a borrower from the investor for a fixed tenure. Bonds or debentures are one of the oldest and simplest of financial instruments. The bond market is the largest financial market in the world with around $123 trillion current outstanding bonds. To put that number in perspective, the combined equity market capitalisation is around $106 trillion. The bond market is also larger than the equity market with yearly issuance of new bonds is almost 35 times more than that of new equities.