Rate of Change (ROC)
Definition
The Rate of Change indicator (ROC) is a momentum oscillator. It calculates the percent change in price between periods. ROC takes the current price and compares it to a price "n" periods (user defined) ago. The calculated value is then plotted and fluctuates above and below a Zero Line. A technical analyst may use Rate of Change (ROC) for; trend identification, and identifying overbought and oversold conditions.
Calculation
n = A user defined number
ROC = [(CurrentClose - Close n periods ago) / (Close n periods ago)] X 100The basics
Rate of Change (ROC) is obviously closely tied to price. When prices are rising or advancing, ROC values remain above the Zero Line (positive) and when they are falling or declining, they remain below the Zero Line (negative).
Also, keep in mind that even though ROC is an oscillator, it is not bounded to a set range. The reason for this is that there is no limit to how far a security can advance in price but of course there is a limit to for far it can decline. If price goes to $0, then it obviously will not decline any further. Because of this, ROC can sometimes appear to be unbalanced.
What to look for
Trend Identification
The Rate of Change (ROC) indicator is can be a good tool for identifying the overall long term trend of a financial instrument. This may not lead to a signal independently, however it can help confirm other, signal-generating conditions.
Overbought and Oversold
As previously mentioned, ROC is not range bound like many other oscillators. Because of this, identifying overbought and oversold conditions can be a little less straightforward. Knowing where to place the overbought and oversold thresholds can be difficult. The best way to accomplish this, is by using research and historical analysis. A technical analyst can look at past price movements compared to the ROC to get a better sense of when an instrument is truly overbought or oversold.
Summary
With the Rate of Change indicator (ROC) it is important to remember that it is best to view it as just one piece of the puzzle. ROC can generate some signals (as seen with overbought and oversold conditions). However, it really becomes most effective when confirming signals or conditions identified by additional technical analysis. Momentum is an extremely important factor when analyzing price movements, and the ROC analyzes momentum quite well. Because of this, it is a valuable technical analysis tool.
Inputs
Length
The time period to be used in calculating the ROC. 9 is the default.
Source
Determines what data from each bar will be used in calculations. Close is the default.
Style
ROC
Can toggle the visibility of the ROC as well as the visibility of a price line showing the actual current price of the ROC. Can also select the ROC Line's color, line thickness and visual style.
Precision
Sets the number of decimal places to be left on the indicator's value before rounding up. The higher this number, the more decimal points will be on the indicator's value.