The Aroon Indicator is used for identifying possible reversal of trends in an underlying security. It is made up of two lines: the "Aroon up", which measures the strength of the uptrend, and the "Aroon down", which measures the strength downtrend. The indicator reports the time, from a starting point, it is taking for the price to reach the highest and lowest points over a given time period; each reported as a percentage of total time. Both the Aroon up and the Aroon down fluctuate between zero and 100. The lower the Aroon up, the weaker the uptrend and the stronger the downtrend are; and vice versa.