The types of companies that have stock trading charts are retail and online brokerage firms such as E*TRADE and Scottrade. Brokerage and banking companies also offer stock trading charts including the websites for TD Ameritrade and Charles Schwab Corporation.
Each of these firms offers its clients software they can install on their home computers. The software can chart an investor's stock to give him a better idea of the stock's performance. E*TRADE gives its clients the ability to customize their charts and use of a variety of indicators to assist in making a stock purchase.