Stock exchange

A stock exchange or bourse is an exchange where stock brokers and traders can buy and/or sell stocks (also called shares), bonds, and other securities. Stock exchanges may also provide facilities for issue and redemption of securities and other financial instruments, and capital events including the payment of income and dividends. Securities traded on a stock exchange include stock issued by listed companies, unit trusts, derivatives, pooled investment products and bonds. Stock exchanges often function as "continuous auction" markets, with buyers and sellers consummating transactions at a central location, such as the floor of the exchange.

To be able to trade a security on a certain stock exchange, it must be listed there. Usually, there is a central location at least for record keeping, but trade is increasingly less linked to such a physical place, as modern markets use electronic networks, which gives them advantages of increased speed and reduced cost of transactions. Trade on an exchange is restricted to brokers who are members of the exchange. In recent years, various other trading venues, such as electronic communication networks, alternative trading systems and "dark pools" have taken much of the trading activity away from traditional stock exchanges.

The initial public offering of stocks and bonds to investors is by definition done in the primary market and subsequent trading is done in the secondary market. A stock exchange is often the most important component of a stock market. Supply and demand in stock markets are driven by various factors that, as in all free markets, affect the price of stocks (see stock valuation).

There is usually no obligation for stock to be issued via the stock exchange itself, nor must stock be subsequently traded on the exchange. Such trading may be off exchange or over-the-counter. This is the usual way that derivatives and bonds are traded. Increasingly, stock exchanges are part of a global securities market.

Early history

Among many other things, the Code of Hammurabi recorded interest-bearing loans.

The idea of debt dates back to the ancient world, as evidenced for example by ancient Mesopotamian clay tablets recording interest-bearing loans. There is little consensus among scholars as to when corporate stock was first traded. Some see the key event as the Dutch East India Company's founding in 1602, while others point to earlier developments. Economist Ulrike Malmendier of the University of California at Berkeley argues that a share market existed as far back as ancient Rome.

In the Roman Republic, which existed for centuries before the Empire was founded, there were societates publicanorum, organizations of contractors or leaseholders who performed temple-building and other services for the government. One such service was the feeding of geese on the Capitoline Hill as a reward to the birds after their honking warned of a Gallic invasion in 390 B.C. Participants in such organizations had partes or shares, a concept mentioned various times by the statesman and orator Cicero. In one speech, Cicero mentions "shares that had a very high price at the time." Such evidence, in Malmendier's view, suggests the instruments were tradable, with fluctuating values based on an organization's success. The societas declined into obscurity in the time of the emperors, as most of their services were taken over by direct agents of the state.

Tradable bonds as a commonly used type of security were a more recent innovation, spearheaded by the Italian city-states of the late medieval and early Renaissance periods.