There are two main types of indicators: leading and lagging. A leading indicator precedes price movements, giving them a predictive quality, while a lagging indicator is a confirmation tool because it follows price movement. A leading indicator is thought to be the strongest during periods of sideways or non-trending trading ranges, while the lagging indicators are still useful during trending periods.
There are also two types of indicator constructions: those that fall in a bounded range and those that do not. The ones that are bound within a range are called oscillators - these are the most common type of indicators. Oscillator indicators have a range, for example between zero and 100, and signal periods where the security is overbought (near 100) or oversold (near zero). Non-bounded indicators still form buy and sell signals along with displaying strength or weakness, but they vary in the way they do this.
The two main ways that indicators are used to form buy and sell signals in technical analysis is through crossovers and divergence. Crossovers are the most popular and are reflected when either the price moves through the moving average, or when two different moving averages cross over each other.The second way indicators are used is through divergence, which happens when the direction of the price trend and the direction of the indicator trend are moving in the opposite direction. This signals to indicator users that the direction of the price trend is weakening.
Indicators that are used in technical analysis provide an extremely useful source of additional information. These indicators help identify momentum, trends, volatility and various other aspects in a security to aid in the technical analysis of trends. It is important to note that while some traders use a single indicator solely for buy and sell signals, they are best used in conjunction with price movement, chart patterns and other indicators.
Accumulation/Distribution Line
The accumulation/distribution line is one of the more popular volume indicators that measures money flows in a security. This indicator attempts to measure the ratio of buying to selling by comparing the price movement of a period to the volume of that period.
Calculated:
Acc/Dist = ((Close - Low) - (High - Close)) / (High - Low) * Period's Volume |
This is a non-bounded indicator that simply keeps a running sum over the period of the security. Traders look for trends in this indicator to gain insight on the amount of purchasing compared to selling of a security. If a security has an accumulation/distribution line that is trending upward, it is a sign that there is more buying than selling.
Average Directional Index
The average directional index (ADX) is a trend indicator that is used to measure the strength of a current trend. The indicator is seldom used to identify the direction of the current trend, but can identify the momentum behind trends.
The ADX is a combination of two price movement measures: the positive directional indicator (+DI) and the negative directional indicator (-DI). The ADX measures the strength of a trend but not the direction. The +DI measures the strength of the upward trend while the -DI measures the strength of the downward trend. These two measures are also plotted along with the ADX line. Measured on a scale between zero and 100, readings below 20 signal a weak trend while readings above 40 signal a strong trend.
Aroon
The Aroon indicator is a relatively new technical indicator that was created in 1995. The Aroon is a trending indicator used to measure whether a security is in an uptrend or downtrend and the magnitude of that trend. The indicator is also used to predict when a new trend is beginning.
The indicator is comprised of two lines, an "Aroon up" line (blue line) and an "Aroon down" line (red dotted line). The Aroon up line measures the amount of time it has been since the highest price during the time period. The Aroon down line, on the other hand, measures the amount of time since the lowest price during the time period. The number of periods that are used in the calculation is dependent on the time frame that the user wants to analyze.
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| Figure 1 |
Aroon Oscillator
An expansion of the Aroon is the Aroon oscillator, which simply plots the difference between the Aroon up and down lines by subtracting the two lines. This line is then plotted between a range of -100 and 100. The centerline at zero in the oscillator is considered to be a major signal line determining the trend. The higher the value of the oscillator from the centerline point, the more upward strength there is in the security; the lower the oscillator's value is from the centerline, the more downward pressure. A trend reversal is signaled when the oscillator crosses through the centerline. For example, when the oscillator goes from positive to negative, a downward trend is confirmed. Divergence is also used in the oscillator to predict trend reversals. A reversal warning is formed when the oscillator and the price trend are moving in an opposite direction.
The Aroon lines and Aroon oscillators are fairly simple concepts to understand but yield powerful information about trends. This is another great indicator to add to any technical trader's arsenal.
