Company stocks are probably the most well known financial instruments in the world. When you buy a stock, you are purchasing a given number of a company's shares that represent ownership of a corporation. Every incorporated company has stock, but only those that are traded on a public exchange are of interest to investors.

Stock market exchanges are found all over the world, from New York to Copenhagen and Hong Kong. Typically, a German exchange will trade German companies and a Swiss exchange Swiss companies, but larger companies are often traded on more than one exchange. The trading takes place on the exchange itself where prices fluctuate according to the laws of supply and demand.