Different indices can be produced based on similar characteristics of stocks in question. There is stock exchange index which is a listing and comparison of all stocks listed in a stock exchange usually a national stock exchange for example, the New York stock exchange(NYE), the Toronto(TXE) or Montreal Stock exchange(MX), the Johannesburg(JsE) or the Nairobi(NSE) stock exchange. Other stocks indices are based on similar activity areas for example the biotechnology companies have their own index. Others can be the mutual fund index, stock market index, and even a stock exchange index or a comparison between stock exchanges. You have to learn to read these indices in order to make decisions on what to buy or sell in stocks. You have to interpret these indices in order to know what the stock prices and make your decisions. Stock trading is an interesting activity that can have huge gains as well as loses but if you are well informed and know how to interpret financial information accurately then you could be a rich person overnight by simply playing your cards right. There are other indices that deal with other factors for example the merck index is a laboratory technician's bible; it lists drugs and chemicals and their behaviours and reactions.