The Rate of Change Percentage is an oscillator that displays the difference in percentage between the current price and the price x-time periods ago. The Rate of change indicator show overbought/oversold areas like many others indicators. Overbought means that the stock price is expected to fall while oversold means that the stock price is expected to fall. But, often extremely overbought/oversold readings usually imply a continuation of the current trend. Formula : (price-prevPrice)/prevPrice