Rate of Change

 
Rate of Change is used to monitor momentum by making direct comparisons between current and past prices on a continual basis. The results can be used to determine the strength of price trends. Note: This study is the same as the Momentum except that Momentum uses subtraction in its calculations while Rate of Change uses division. The resulting lines of these two studies operated over the same data will look exactly the same - only the scale values will differ.

The Price Rate-of-Change ("ROC") indicator displays the difference between the current price and the price x-time periods ago. The difference can be displayed in either points or as a percentage. The Momentum indicator displays the same information, but expresses it as a ratio.  

When the Rate-of-Change displays the price change in points, it subtracts the price x-time periods ago from today’s price:

Today’s Close – Close x periods ago

When the Rate-of-Change displays the price change as a percentage, it divides the price change by price x-time period’s ago: