The Aroon Oscillator is a technical indicator that was developed to identify trends in trading.As the name implies, the aroon oscillator uses two lines to measure market activity. The difference between these two lines represents either an uptrend or a downtrend in the stock market over time.When this value is positive, it means that there has been an accumulation of bullish sentiment on that particular security over time, and vice versa for negative values on the oscillator.