Stock Valuation

There are several methods used to value companies and their stocks. They attempt to give an estimate of their fair value, by using fundamental economic criteria. This theoretical valuation has to be perfected with market criteria, as the final purpose is to determine potential market prices.
 
The most theoretically sound stock valuation method is called income valuation or the discounted cash flow (DCF) method, involving discounting the profits (dividends, earnings, or cash flows) the stock will bring to the stockholder in the foreseeable future, and a final value on disposition. The discount rate normally has to include a risk premium which is commonly based on the capital asset pricing model.

The Gordon model or Gordon's growth model is the best known of a class of discounted dividend models. It assumes that dividends will increase at a constant growth rate (less than the discount rate) forever.  The valuation is given by the formula:

P = estimated stock price
D = last dividend paid
k = discount rate
g = the growth rate of the dividends

The P/E method is perhaps the most commonly used valuation method in the stock brokerage industry. By using comparison firms, a target price/earnings (or P/E) ratio is selected for the company, and then the future earnings of the company are estimated. The valuation's fair price is simply estimated earnings times target P/E. This model is essentially the same model as Gordon's model, if k-g is estimated as the dividend payout ratio (D/E) divided by the target P/E ratio. 

Bonds

A bond is a debt security, in which the authorized issuer owes the holders a debt and is obliged to repay the principal and interest (the coupon) at a later date, termed maturity. Other stipulations may also be attached to the bond issue, such as the obligation for the issuer to provide certain information to the bond holder, or limitations on the behavior of the issuer. Bonds are generally issued for a fixed term (the maturity) longer than ten years. U.S Treasury securities issue debt with life of ten years or more, which is a bond. New debt between one year and ten years is a "note", and new debt less than a year is a "bill".

A bond is simply a loan, but in the form of a security, although terminology used is rather different. The issuer is equivalent to the borrower, the bond holder to the lender, and the coupon to the interest. Bonds enable the issuer to finance long-term investments with external funds. Certificates of deposit (CDs) or commercial paper are considered money market instruments.

In some nations, both bonds and notes are used irrespective of the maturity. Market participants normally use bonds for large issues offered to a wide public, and notes for smaller issues originally sold to a limited number of investors. There are no clear demarcations. There are also "bills" which usually denote fixed income securities with three years or less, from the issue date, to maturity. Bonds have the highest risk, notes are the second highest risk, and bills have the least risk. This is due to a statistical measure called duration, where lower durations have less risk, and are associated with shorter term obligations.

Bonds and stocks are both securities, but the difference is that stock holders own a part of the issuing company (have an equity stake), whereas bond holders are in essence lenders to the issuer. Also bonds usually have a defined term, or maturity, after which the bond is redeemed whereas stocks may be outstanding indefinitely. An exception is a consol bond, which is a perpetuity (i.e. bond with no maturity).

Bond Valuation

Bond valuation is the process of determining the fair price of a bond. As with any security or capital investment, the fair value of a bond is the present value of the stream of cash flows it is expected to generate. Hence, the price or value of a bond is determined by discounting the bond's expected cash flows to the present using the appropriate discount rate.

The fair price of a straight bond with no embedded option is determined by discounting the expected cash flows: