If you are looking striving to identify and track patterns in the charts of particular companies, look no further than Yahoo Finance. All you have to do is type in the company name or symbol where indicated on the screen, and then select the "get quotes" button. When you are on the page about quotes, click on "historical prices" which should be a link on the left hand side of the menu page. This will then open a new page where investors may then key in whatever search parameters or choices they are looking for.
For example, if you are looking to chart a pattern for a certain time frame, you may do that too. You only have to select the button for the particular time-related value you are interested in: like monthly, weekly, daily, or dividends only information.
In some cases, data may go back years or even decades so you may be surprised how much information you'll be able to find by studying the patterns closely. The date-related search should give you a table of stock prices, including closing price, high, open, low, and even volume, or the number of shares that were sold. You should also be able to find information on adjusted closing prices, which helps take into account anytime the stock has split, as well as other unusual or atypical adjustments and also dividends.
In addition to Yahoo Finance, MSN has a great website called Money Central. They are well-known for super chart graphics which can make identifying patterns even easier. To find this, go to the current informational page, enter in a stock symbol (just as you did with Yahoo), and click on "historical charts". This link will take you to a section of the website with a huge variety of choices that will help you determine what type of specific data you want.
Like Yahoo, you may also select which time frame you want information on for a stock, either for the past few days, months, years, or even five years or more. Or if you have a specific time frame in mind that you want to enter in, you may do that as well. To continue with your search even further, try going to the Customize Chart section of the website where you may chose several different overlays.