Bar Chart

Perhaps the most popular charting method is the bar chart. The high, low and close are required to form the price plot for each period of a bar chart. The high and low are represented by the top and bottom of the vertical bar and the close is the short horizontal line crossing the vertical bar. On a daily chart, each bar represents the high, low and close for a particular day. Weekly charts would have a bar for each week based on Friday's close and the high and low for that week.

Bar charts can also be displayed using the open, high, low and close. The only difference is the addition of the open price, which is displayed as a short horizontal line extending to the left of the bar. Whether or not a bar chart includes the open depends on the data available.

Bar charts can be effective for displaying a large amount of data. Using candlesticks, 200 data points can take up a lot of room and look cluttered. Line charts show less clutter, but do not offer as much detail (no high-low range). The individual bars that make up the bar chart are relatively skinny, which allows users the ability to fit more bars before the chart gets cluttered. If you are not interested in the opening price, bar charts are an ideal method for analyzing the close relative to the high and low. In addition, bar charts that include the open will tend to get cluttered quicker. If you are interested in the opening price, candlestick charts probably offer a better alternative.

Candlestick Chart

Originating in Japan over 300 years ago, candlestick charts have become quite popular in recent years. For a candlestick chart, the open, high, low and close are all required. A daily candlestick is based on the open price, the intraday high and low, and the close. A weekly candlestick is based on Monday's open, the weekly high-low range and Friday's close..

The beauty of point & figure charts is their simplicity. Little or no price movement is deemed irrelevant and therefore not duplicated on the chart. Only price movements that exceed specified levels are recorded. This focus on price movement makes it easier to identify support and resistance levels, bullish breakouts and bearish breakdowns. This P&F article has a more detailed explanation of point & figure charts.

There are two methods for displaying the price scale along the y-axis: arithmetic and logarithmic. An arithmetic scale displays 10 points (or dollars) as the same vertical distance no matter what the price level. Each unit of measure is the same throughout the entire scale. If a stock advances from 10 to 80 over a 6-month period, the move from 10 to 20 will appear to be the same distance as the move from 70 to 80. Even though this move is the same in absolute terms, it is not the same in percentage terms.

A logarithmic scale measures price movements in percentage terms. An advance from 10 to 20 would represent an increase of 100%. An advance from 20 to 40 would also be 100%, as would an advance from 40 to 80. All three of these advances would appear as the same vertical distance on a logarithmic scale. Most charting programs refer to the logarithmic scale as a semi-log scale, because the time axis is still displayed arithmetically.

The chart above uses the 4th-Quarter performance of VeriSign to illustrate the difference in scaling. On the semi-log scale, the distance between 50 and 100 is the same as the distance between 100 and 200. However, on the arithmetic scale, the distance between 100 and 200 is significantly greater than the distance between 50 and 100.

Key points on the benefits of arithmetic and semi-log scales:

                       Arithmetic scales are useful when the price range is confined within a relatively tight range.

                       Arithmetic scales are useful for short-term charts and trading. Price movements (particularly for stocks) are shown in absolute dollar terms and reflect movements dollar for dollar.

                        Semi-log scales are useful when the price has moved significantly, be it over a short or extended time frame

                       Trend lines tend to match lows better on semi-log scales.

                       Semi-log scales are useful for long-term charts to gauge the percentage movements over a long period of time. Large movements are put into perspective.

§                        Stocks and many other securities are judged in relative terms through the use of ratios such as PE, Price/Revenues and Price/Book. With this in mind, it also makes sense to analyze price movements in percentage terms.

Even though many different charting techniques are available, one method is not necessarily better than the other. The data may be the same, but each method will provide its own unique interpretation, with its own benefits and drawbacks. A breakout on the point & figure chart may not occur in unison with a breakout in a candlestick chart. Signals that are available on candlestick charts may not appear on bar charts. How the security's price is displayed, be it a bar chart or candlestick chart, with an arithmetic scale or semi-log scale, is not the most important aspect. After all, the data is the same and price action is price action. When all is said and done, it is the analysis of the price action that separates successful technicians from not-so-successful technicians. The choice of which charting method to use will depend on personal preferences and trading or investing styles. Once you have chosen a particular charting methodology, it is probably best to stick with it and learn how best to read the signals. Switching back and forth may cause confusion and undermine the focus of your analysis. Faulty analysis is rarely caused by the chart. Before blaming your charting method for missing a signal, first look at your analysis.

                  Dedication: Learn the basics of chart analysis, apply your knowledge on a regular basis, and continue your development.

                   Focus: Limit the number of charts, indicators and methods you use. Learn how to use them, and learn how to use them well.

                   Consistency: Maintain your charts on a regular basis and study them often (daily if possible).