The Aroon Oscillator is a technical analysis tool used to measure the strength and direction of a current trend in a financial market. It is derived from the Aroon Indicator, which was developed by Tushar Chande in 1995.

The Aroon Oscillator is calculated by subtracting the Aroon Down value from the Aroon Up value. The Aroon Up measures the number of periods since the highest high within a given period, while the Aroon Down measures the number of periods since the lowest low within a given period. By subtracting these values, the Aroon Oscillator oscillates around zero.

The oscillator's values range between -100 and +100, where positive values indicate an uptrend and negative values indicate a downtrend. A reading of zero suggests a balanced or sideways market.

Traders and analysts use the Aroon Oscillator to identify potential trend reversals, confirm the strength of a trend, and generate buy or sell signals. When the oscillator crosses above zero, it may signal the start of an uptrend, while a crossover below zero may indicate the start of a downtrend.