Stocks, also known as equities, are shares of ownership that entitle the holder to a part of a company's assets and earnings. The stock market is where these shares are bought and sold. There are 60 major stock exchanges around the world and 16 of them each have a market capitalization of over $1 trillion. Both large players like banks or hedge funds and small investors participate in this market. The stock market operates on a system of supply and demand and has opportunities for long term investors and for day traders..