Image you are a market. You know enough, not necessarily everything, but enough for having no fear what ever happens. You claim you are the guardian of the market and have unlimited backup. Now an outsider comes in , buys, and sells in your market. You do business with him or her. Now more outsiders come in, you fluctuate the price to make buyers buy expensive and sellers sell cheap. To track more outsiders, you let dealers to do the job for you. Meanwhile you dress your business as attractive as possible so more outsiders will do business with you. This is usually by doing the job on yourself when things are slow. So more price fluctuation. Track more outsiders. You love gamblers. Now remember the dealers. They also do their jobs to track more outsiders in ads, news, commentary, and even Internet sites like ET. You bet. There are more representatives from marker makers and brokers on ET than real ET users. Same time more involvment from tax man, accountant, data/software vendors etc. etc.. The goal is like everywhere else, the customers should be made feel comfortable. This is a market.