Trading

Participants in the stock market range from small individual stock investors to large hedge fund traders, who can be based anywhere. Their orders usually end up with a professional at a stock exchange, who executes the order.

Some exchanges are physical locations where transactions are carried out on a trading floor, by a method known as open outcry. This type of auction is used in stock exchanges and commodity exchanges where traders may enter "verbal" bids and offers simultaneously. The other type of stock exchange is a virtual kind, composed of a network of computers where trades are made electronically via traders.

Actual trades are based on an auction market model where a potential buyer bids a specific price for a stock and a potential seller asks a specific price for the stock. (Buying or selling at market means you will accept any ask price or bid price for the stock, respectively.) When the bid and ask prices match, a sale takes place, on a first-come-first-served basis if there are multiple bidders or askers at a given price.

The purpose of a stock exchange is to facilitate the exchange of securities between buyers and sellers, thus providing a marketplace (virtual or real). The exchanges provide real-time trading information on the listed securities, facilitating price discovery.

The New York Stock Exchange.

The New York Stock Exchange is a physical exchange, also referred to as a listed exchange – only stocks listed with the exchange may be traded. Orders enter by way of exchange members and flow down to a floor broker, who goes to the floor trading post specialist for that stock to trade the order. The specialist's job is to match buy and sell orders using open outcry. If a spread exists, no trade immediately takes place—in this case the specialist should use his/her own resources (money or stock) to close the difference after his/her judged time. Once a trade has been made the details are reported on the "tape" and sent back to the brokerage firm, which then notifies the investor who placed the order. Although there is a significant amount of human contact in this process, computers play an important role, especially for so-called "program trading".

In 12th century France the courtiers de change were concerned with managing and regulating the debts of agricultural communities on behalf of the banks. As these men also traded in debts, they could be called the first brokers.

Some stories suggest that the origins of the term "bourse" came from the Latin bursa meaning a bag because, in 13th century Bruges, the sign of a purse (or perhaps three purses), was hung on the front of the house where merchants met.

The story may well be apocryphal, however it is possible that in the late 13th century commodity traders in Bruges gathered inside the house of the Van der Burse family (for some a Venetian family with original name "Della Borsa" and used three leather bags as coat-of-arms), and in 1309 they institutionalized this until now informal meeting and became the "Bruges Bourse." The idea spread quickly around Flanders and neighboring counties and "Bourses" soon opened in Ghent and Amsterdam.

In the middle of the 13th century, Venetian bankers began to trade in government securities. In 1351, the Venetian Government outlawed spreading rumors intended to lower the price of government funds. There were people in Pisa, Verona, Genoa and Florence who also began trading in government securities during the 14th century. This was only possible because these were independent city states ruled by a council of influential citizens, not by a duke.

The Dutch later started joint stock companies, which let shareholders invest in business ventures and get a share of their profits—or losses. In 1602, the Dutch East India Company issued the first shares on the Amsterdam Stock Exchange. It was the first company to issue stocks and bonds. In 1688, the trading of stocks began on a stock exchange in London.

On May 17, 1792, in order to more easily trade cotton, twenty-four supply brokers signed the Buttonwood Agreement outside 68 Wall Street in New York underneath a buttonwood tree. On March 8, 1817, properties got renamed to New York Stock & Exchange Board. In the 19th century, exchanges (generally famous as futures exchanges) got substantiated to trade futures contracts and then choices contracts.

There are now a large number of stock exchanges in the world.