Approximate valuation approaches

Average growth approximation: Assuming that two stocks have the same earnings growth, the one with a lower P/E is a better value. 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.

Constant growth approximation: The Gordon model or Gordon's growth 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:

and the following table defines each symbol:

Symbol	Meaning	Units
	estimated stock price	$ or € or £
	last dividend paid	$ or € or £
	discount rate	%
	the growth rate of the dividends	%

Fundamental criteria (fair value)

he most theoretically sound stock valuation method, called income valuation or the discounted cash flow (DCF) method, involves discounting of 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 discounted rate normally includes a risk premium which is commonly based on the capital asset pricing model.

Stock valuation

here 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.

Gallery

Bombay Stock Exchange	Frankfurt Stock Exchange	Hong Kong Stock Exchange	London Stock Exchange
Madrid Stock Exchange	Mexican Stock Exchange	Montreal Stock Exchange	Osaka Securities Exchange
Milan Stock Exchange	Philippine Stock Exchange	São Paulo Stock Exchange	Shanghai Stock Exchange
SWX Swiss Exchange	Taiwan Stock Exchange	Tokyo Stock Exchange	Toronto Stock Exchange

The future of stock exchanges

The future of stock trading appears to be electronic, as competition is continually growing between the remaining traditional New York Stock Exchange specialist system against the relatively new, all Electronic Communications Networks, or ECNs. ECNs point to their speedy execution of large block trades, while specialist system proponents cite the role of specialists in maintaining orderly markets, especially under extraordinary conditions or for special types of orders.

The ECNs contend that an array of special interests profit at the expense of investors in even the most mundane exchange-directed trades. Machine-based systems, they argue, are much more efficient, because they speed up the execution mechanism and eliminate the need to deal with an intermediary.

Historically, the 'market' (which, as noted, encompasses the totality of stock trading on all exchanges) has been slow to respond to technological innovation. Conversion to all-electronic trading could erode/eliminate the trading profits of floor specialists and the NYSE's "upstairs traders."

William Lupien, founder of the Instinet trading system and the OptiMark system, has been quoted as saying "I'd definitely say the ECNs are winning... Things happen awfully fast once you reach the tipping point. We're now at the tipping point."

Congress mandated the establishment of a national market system of multiple exchanges in 1975. Since then, ECNs have been developing rapidly.

One example of improved efficiency of ECNs is the prevention of front running, by which manual Wall Street traders use knowledge of a customer's incoming order to place their own orders so as to benefit from the perceived change to market direction that the introduction of a large order will cause. By executing large trades at lightning speed without manual intervention, ECNs make impossible this illegal practice, for which several NYSE floor brokers were investigated and severely fined in recent years. Under the specialist system, when the market sees a large trade in a name, other buyers are immediately able to look to see how big the trader is in the name, and make inferences about why s/he is selling or buying. All traders who are quick enough are able to use that information to anticipate price movements.

ECNs have changed ordinary stock transaction processing (like brokerage services before them) into a commodity-type business. ECNs could regulate the fairness of initial public offerings (IPOs), oversee Hambrecht's OpenIPO process, or measure the effectiveness of securities research and use transaction fees to subsidize small- and mid-cap research efforts.

Some, however, believe the answer will be some combination of the best of technology and "upstairs trading" — in other words, a hybrid model.

Trading 25,000 shares of General Electric stock (recent quote: $34.76; recent volume: 44,760,300) would be a relatively simple e-commerce transaction; trading 100 shares of Berkshire Hathaway Class A stock (recent quote: $139,700.00; recent volume: 850) may never be. The choice of system should be clear (but always that of the trader), based on the characteristics of the security to be traded.

Even with ECNs forming an important part of a national market system, opportunities presumably remain to profit from the spread between the bid and offer price. That is especially true for investment managers that direct huge trading volume, and own a stake in an ECN or specialist firm. For example, in its individual stock-brokerage accounts, "Fidelity Investments runs 29% of its undesignated orders in NYSE-listed stocks, and 37% of its undesignated market orders through the Boston Stock Exchange, where an affiliate controls a specialist post."

Fidelity says these arrangements are governed by a separate brokerage "order-flow management" team, which seeks to obtain the best possible execution for customers, and that its execution is highly rated.

Other types of exchanges

In the 19th century, exchanges were opened to trade forward contracts on commodities. Exchange traded forward contracts are called futures contracts. These commodity exchanges later started offering future contracts on other products, such as interest rates and shares, as well as options contracts. They are now generally known as futures exchanges.

Ownership

Stock exchanges originated as mutual organizations, owned by its member stock brokers. There has been a recent trend for stock exchanges to demutualize, where the members sell their shares in an initial public offering. In this way the mutual organization becomes a corporation, with shares that are listed on a stock exchange. Examples are Australian Securities Exchange (1998), Euronext (merged with New York Stock Exchange), NASDAQ (2002), the New York Stock Exchange (2005), Bolsas y Mercados Españoles, and the São Paulo Stock Exchange (2007).