By TheStreet Staff What Are Bond Ratings?A bond is a loan made from an investor to a corporation or a government entity. In return for their investment, the bondholder expects to be repaid their principal, or original investment amount, along with interest, which is known as the coupon. The longer the investment period or the riskier the company they are lending money to, the greater the amount of interest the bondholder will receive. But how can investors tell how risky a bond is? All bonds receive a financial rating in the form of a letter grade. This illustrates their creditworthiness, tell…