What Is A Chart?
In technical analysis, a chart is simply a graphical representation of a series of prices over a set time frame. It may show a stock’s price movement over a one-year period, where each point on the graph represents the closing price for each day the stock is traded.
The figure on the right is an example of a basic chart. It is a representation of the price movements of a stock over a 1.5-year period. The bottom of the graph, running horizontally (x-axis), is the date or time scale. On the right hand side, running vertically (y-axis), the price of the security is shown.
By looking at the chart, we see that in October 2004 (Point 1), the price of this stock was around P245, whereas in June 2005 (Point 2), the stock’s price is around P265. This tells us that the stock has risen between October 2004 and June 2005.
There are several things that you should be aware of when looking at a chart, as these factors can affect the information that is provided. They include thetime scale, the price scale, and the price point properties used.
The time scale refers to the range of dates at the bottom of the chart, which can vary from decades to seconds. The most frequently used time scales are intraday, daily, weekly, monthly, quarterly and annually. The shorter the time frame, the more detailed the chart. Each data point can represent the closing price of the period or show the open, the high, the low and the close depending on the chart used.
Intraday charts plot price movement within the period of one day. This means that the time scale could be as short as five minutes or could cover the whole trading day from the opening bell to the closing bell.
Daily charts are comprised of a series of price movements in which each price point on the chart is a full day’s trading condensed into one point. Again, each point on the graph can be simply the closing price or can entail the open, high, low and close for the stock over the day. These data points are spread out over weekly, monthly and even yearly time scales to monitor both short-term and intermediate trends in price movement.
Weekly, monthly, quarterly and yearly charts are used to analyze longer term trends in the movement of a stock’s price. Each data point in these graphs will be a condensed version of what happened over the specified period. So for a weekly chart, each data point will be a representation of the price movement of the week.
For example, if you are looking at a chart of weekly data spread over a five-year period and each data point is the closing price for the week, the price that is plotted will be the closing price on the last trading day of the week, which is usually a Friday.
The Price Scale And Price Point Properties
The price scale is on the right-hand side of the chart. It shows a stock’s current price and compares it to past data points. This may seem like a simple concept in that the price scale goes from lower prices to higher prices as you move along the scale from the bottom to the top.
The problem, however, is in the structure of the scale itself. A scale can either be constructed in a linear (arithmetic) or logarithmic way, and both of these options are available on most charting services.
If a price scale is constructed using a linear scale, the space between each price point (10, 20, 30, 40) is separated by an equal amount. A price move from 10 to 20 on a linear scale is the same distance on the chart as a move from 40 to 50. In other words, the price scale measures moves in absolute terms and does not show the effects of percent change.
If a price scale is in logarithmic terms, then the distance between points will be equal in terms of percent change. A price change from 10 to 20 is a 100% increase in the price while a move from 40 to 50 is only a 25% change, even though they are represented by the same distance on a linear scale.
On a logarithmic scale, the distance of the 100% price change from 10 to 20 will not be the same as the 25% change from 40 to 50. In this case, the move from 10 to 20 is represented by a larger space one the chart, while the move from 40 to 50, is represented by a smaller space because, percentage-wise, it indicates a smaller move.
In the figure above, the logarithmic price scale on the right leaves the same amount of space between 10 and 20 as it does between 20 and 40 because these both represent 100% increases.
There are four main types of charts that are used by investors and traders, depending on the information that they are seeking and their individual skill levels: the line chart, the bar chart, the candlestick chart, and the point and figure chart.
While we will no longer discuss the point and figure chart, you will see in the following sections that even if the data used to create the charts is the same, the way the data is shown in the different chart types is different.
The most basic of the four charts is the line chart because it represents only the closing prices over a set period of time.
As you can see on the left, the line is formed by connecting the closing prices over the time frame.
Line charts do not provide visual information of the trading range for the individual points such as the high, low and opening prices. However, the closing price is often considered to be the most important price in stock data compared to the high and low for the day and this is why it is the only value used in line charts.
The bar chart expands on the line chart by adding several more key pieces of information to each data point. The chart is made up of a series of vertical lines that represent each data point. This vertical line represents the high and low for the trading period, along with the closing price.
The close and open are represented on the vertical line by a horizontal dash. The opening price on a bar chart is illustrated by the dash that is located on the left side of the vertical bar.
Conversely, the close is represented by the dash on the right. Generally, if the left dash (open) is lower than the right dash (close) then the bar will be shaded black, representing an up period for the stock, which means it has gained value.
A bar that is colored red signals that the stock has gone down in value over that period. When this is the case, the dash on the right (close) is lower than the dash on the left (open).
The candlestick chart is similar to a bar chart, but it differs in the way that it is visually constructed. Similar to the bar chart, the candlestick also has a thin vertical line showing the period’s trading range.
The difference comes in the formation of a wide bar on the vertical line, which illustrates the difference between the open and close. And, like bar charts, candlesticks also rely heavily on the use of colors to explain what has happened during the trading period.
A major problem with the candlestick color configuration, however, is that different sites use different standards; therefore, it is important to understand the candlestick configuration used at the chart site you are working with.
There are two color constructs for days up and one for days that the price falls. When the price of the stock is up and closes above the opening trade, the candlestick will usually be white or clear.
If the stock has traded down for the period, then the candlestick will usually be red or black, depending on the site. If the stock’s price has closed above the previous day’s close but below the day’s open, the candlestick will be black or filled with the color that is used to indicate an up day.
A chart pattern is a distinct formation on a stock chart that creates a trading signal, or a sign of future price movements. Chartists use these patterns to identify current trends and trend reversals and to trigger buy and sell signals.
In Part 1 of this series, we talked about the three assumptions of technical analysis, one of which is that history repeats itself. The theory behind chart patters is based on this assumption.
The idea is that certain patterns are seen many times, and that these patterns signal a certain high probability move in a stock! Based on the historic trend of a chart pattern setting up a certain price movement, chartists look for these patterns to identify trading opportunities.
While there are general ideas and components to every chart pattern, there is no chart pattern that will tell you with 100% certainty where a security is headed. This creates some leeway and debate as to what a good pattern looks like, and is a major reason why charting is often seen as more of an art than a science.
There are two types of patterns within this area of technical analysis: reversal and continuation. A reversal pattern signals that a prior trend will reverse upon completion of the pattern. A continuation pattern, on the other hand, signals that a trend will continue once the pattern is complete.
These patterns can be found over charts of any timeframe. Let us tackle some of the more popular chart patterns.
Head And Shoulders
This is one of the most popular and reliable chart patterns in technical analysis. Head and shoulders is a reversal chart pattern that when formed, signals that the security is likely to move against the previous trend.
As you can see in the figure, there are two versions of the head and shoulders chart pattern. Head and shoulders top (shown on the left) is a chart pattern that is formed at the high of an upward movement and signals that the upward trend is about to end.
Head and shoulders bottom, also known as inverse head and shoulders (shown on the right) is the lesser known of the two, but is used to signal a reversal in a downtrend.
Both of these head and shoulders patterns are similar in that there are four main parts: two shoulders, a head, and a neckline. Also, each individual head and shoulder is comprised of a high and a low.
For example, in the head and shoulders top image shown on the left side in the figure above, the left shoulder is made up of a high followed by a low. In this pattern, the neckline is a level of support or resistance.
Remember that an upward trend is a period of successive rising highs and rising lows. The head and shoulders chart pattern, therefore, illustrates a weakening in a trend by showing the deterioration in the successive movements of the highs and lows.
Cup And Handle
A cup and handle chart is a bullish continuation pattern in which the upward trend has paused but will continue in an upward direction once the pattern is confirmed. As you can see in the figure, this price pattern forms what looks like a cup, which is preceded by an upward trend. The handle follows the cup formation and is formed by a generally downward/sideways movement in the security’s price.
Once the price movement pushes above the resistance lines formed in the handle, the upward trend can continue. There is a wide ranging time frame for this type of pattern, with the span ranging from several months to more than a year.
CDouble Tops And Bottoms
This chart pattern is another well-known pattern that signals a trend reversal! It is considered to be one of the most reliable and commonly used. These patterns are formed after a sustained trend and signal to chartists that the trend is about to reverse.
Double tops and bottoms are created when a price movement tests support or resistance levels twice and is unable to break through. This pattern is often used to signal intermediate and long-term trend reversals.
In the case of the double top pattern on the left, the price movement has twice tried to move above a certain price level. After two unsuccessful attempts at pushing the price higher, the trend reverses and the price heads lower.
In the case of a double bottom on the right, the price movement has tried to go lower twice, but has found support each time. After the second bounce off of the support, the security enters a new trend and heads upward.
Triangles are some of the most well-known chart patterns used in technical analysis. The three types of triangles, which vary in construct and implication, are the symmetrical triangle, ascending triangle, and descending triangle. These chart patterns are considered to last anywhere from a couple of weeks to several months.
The symmetrical triangle in the figure is a pattern in which two trendlines converge toward each other. This pattern is neutral in that a breakout to the upside or downside is a confirmation of a trend in that direction.
In an ascending triangle, the upper trendline is flat, while the bottom trendline is upward sloping. This is generally thought of as a bullish pattern in which chartists look for an upside breakout.
In a descending triangle, the lower trendline is flat and the upper trendline is descending. This is generally seen as a bearish pattern where chartists look for a downside breakout.
Flag And Pennant
These two short-term chart patterns are continuation patterns that are formed when there is a sharp price movement followed by a generally sideways price movement. This pattern is then completed upon another sharp price movement in the same direction as the move that started the trend. The patterns are generally thought to last from one to three weeks.
As you can see in the figure, there is little difference between a pennant and a flag. The main difference between these price movements can be seen in the middle section of the chart pattern.
In a pennant, the middle section is characterized by converging trendlines, much like what is seen in a symmetrical triangle.
The middle section on the flag pattern, on the other hand, shows a channel pattern, with no convergence between the trendlines. In both cases, the trend is expected to continue when the price moves above the upper trendline.
The wedge chart pattern can be either a continuation or reversal pattern. It is similar to a symmetrical triangle except that the wedge pattern slants in an upward or downward direction, while the symmetrical triangle generally shows a sideways movement. The other difference is that wedges tend to form over longer periods, usually from three to six months.
The fact that wedges are classified as both continuation and reversal patterns can make reading signals confusing. However, at the most basic level, a falling wedge is bullish and a rising wedge is bearish.
In the figure on the right, we have a falling wedge in which two trendlines are converging in a downward direction. If the price was to rise above the upper trendline, it would form a continuation pattern, while a move below the lower trendline would signal a reversal pattern.
Triple Tops And Bottoms
Triple tops and triple bottoms are another type of reversal chart pattern in chart analysis. These are not as prevalent in charts as head and shoulders and double tops and bottoms, but they act in a similar fashion.
These two chart patterns, as can be seen in the figure on the left, are formed when the price movement tests a level of support or resistance three times and is unable to break through; this signals a reversal of the prior trend.
Confusion can form with triple tops and bottoms during the formation of the pattern because they can look similar to other chart patterns. After the first two support/resistance tests are formed in the price movement, the pattern will look like a double top or bottom, which could lead a chartist to enter a reversal position too soon.
A rounding bottom, also referred to as a saucer bottom, is a long-term reversal pattern that signals a shift from a downward trend to an upward trend. This pattern is traditionally thought to last anywhere from several months to several years.
A rounding bottom chart pattern looks similar to a cup and handle pattern but without the handle. The long-term nature of this pattern and the lack of a confirmation trigger, such as the handle in the cup and handle, make it a difficult pattern to trade.