1. Par value is the amount of money the investor will receive once the bond matures, meaning that the entity that sold the bond will return to the investor the original amount that it was loaned, called the principal. As mentioned earlier, par value for corporate bonds is normally $1000, although for government bonds it can be much higher.

3. The maturity date is the date when the bond issuer has to return the principal to the lender. After the debtor pays back the principal, it is no longer obligated to make interest payments. Sometimes a company will decide to "call" its bond, meaning that it is giving the lenders their money back before the maturity date of the bond. All corporate bonds specify whether they can be called and how soon they can be called. Federal government bonds are never called, although state and local government bonds can be called.

New Articles on Values of Bonds

How to Calculate Bond Yields

The key piece of information to know about a bond in order to compare it with other potential investments is the yield. You can calculate the yield on a bond by dividing the amount of interest it will pay over the course of a year by the current price of the bond.

If a bond that cost $1000 pays $75 a year in interest, then its current yield is $75 divided by $1000, or 7.5%.

Trading and valuing bonds

The interest rate that the issuer of a bond must pay is influenced by a variety of factors, such as current market interest rates, the length of the term and the credit worthiness of the issuer. Since these factors are likely to change over time, the market value of a bond can vary after it is issued. Because of these differences in market value, bonds are priced in terms of percentage of par value. Bonds are not necessarily issued at par (100% of face value, corresponding to a price of 100), but all bond prices converge to par at the moment before they reach maturity. At other times, prices can either rise (bond is priced at greater than 100), which is called trading at a premium, or fall (bond is priced at less than 100), which is called trading at a discount. Most government bonds are denominated in units of $1000, if in the United States, or in units of one hundred pounds, if in the United Kingdom. Hence, a deep discount US bond, selling at a price of 75.26, indicates a selling price of $752.60 per bond sold. (Often, bond prices are quoted in points and thirty-seconds of a point, rather than in decimal form.) Some short-term bonds, such as the U.S. T-Bill, are always issued at a discount, and pay par amount at maturity rather than paying coupons. This is called a discount bond.

The market price of a bond is the present value of all future interest and principal payments of the bond discounted at the bond's yield, or rate of return. The yield represents the current market interest rate for bonds with similar characteristics. The yield and price of a bond are inversely related so that when market interest rates rise, bond prices generally fall and vice versa.

The market price of a bond may include the accrued interest since the last coupon date. (Some bond markets include accrued interest in the trading price and others add it on explicitly after trading.) The price including accrued interest is known as the "flat" or "dirty price". (See also Accrual bond.) The price excluding accrued interest is sometimes known as the "clean" price.

The interest rate adjusted for the current price of the bond is called the "current yield" or "earnings yield" (this is the nominal yield multiplied by the par value and divided by the price).

Taking into account the expected capital gain or loss (the difference between the current price and the redemption value) gives the "redemption yield": roughly the current yield plus the capital gain (negative for loss) per year until redemption.

The relationship between yield and maturity for otherwise identical bonds is called a yield curve.

Unlike the case for many stock or share markets, bonds often do not trade on a centralized exchange or trading system. Rather, in most developed bond markets such as the U.S., Japan and western Europe, bonds trade in decentralized, dealer-based over-the-counter markets. In such a market, market liquidity is provided by dealers and other market participants committing risk capital to trading activity. In the bond market, when an investor buys or sells a bond, the counterparty to the trade is almost always a bank or securities firm acting as a dealer. In some cases, when a dealer buys a bond from an investor, the dealer carries the bond "in inventory." The dealer's position is then subject to risks of price fluctuation. In other cases, the dealer immediately resells the bond to another investor.

Also unlike the case for many stock markets, investors generally do not pay brokerage commissions to dealers with whom they buy or sell bonds. Rather, dealers earn revenue for trading with their investor customers by means of the spread, or difference, between the price at which the dealer buys a bond from one investor--the "bid" price--and the price at which he or she sells the same bond to another investor--the "ask" or "offer" price. The bid/offer spread represents the total transaction cost associated with transferring a bond from one investor to another.