Comparing stock prices is a good way to determine if a given stock is a good value relative to other stocks in its sector, or just to examine stocks priced above or below a given threshold. It is easy to compare stock prices on the Internet, and many tools are available to screen stocks according to your own criteria. Using fundamental analysis to compare stock prices is the traditional approach to long-term investing, while using technical analysis to quantify movements in stock price can be an excellent short-term approach.
Analyze a company's price-to-earnings ratio. The most traditional method of determining whether a stock is valued properly is to analyze this ratio of its price to the company's annual earnings per share. The P/E ratio is at the core of fundamental analysis.
For example, if XYZ earned $8.50 per share last year and the stock is trading at $125 per share, the stock has a P/E ratio of approximately 15-to-1. In other words, the stock is trading at 15 times the annual earnings. Generally, the lower the P/E ratio, the better value the stock represents. Older blue chip companies typically trade at eight to 12 times earnings, while highflying technology companies can trade at 30 to 40 times earnings or more. A company can even be losing money and trade at a high price.
Compare a stock price to other companies in the same sector. It stands to reason that two or more publicly traded companies in the same business should be roughly similar in stock price, but this is rarely the case. By analyzing an entire business sector (airlines, banking, construction, etc.), you get a feel for which are the best performing stocks in that particular sector. Comparing the stock prices side by side often reveals which companies are best poised for growth in that sector. Google Finance offers excellent sector coverage.
Analyze the biggest winners and losers. Most stock-quoting systems will give you access to the biggest price and percentage movers of the day. Stocks that gained or lost the greatest dollar amount or percentage make for interesting analysis and potential investments. Stocks that lost much of their value one day might be due for a nice rebound the next. Likewise, by studying the stocks that gained a great deal in a given day, you may be able to identify other stocks poised to make a similar move.