The Accelerator Oscillator - (AC) is also known as the Acceleration / Deceleration Oscillator.

The Accelerator Oscillator (AC) indicator measures the acceleration or deceleration of the price.

The Accelerator Oscillator (AC) indicator will change its direction before the change in price. 

The Accelerator Oscillator (AC) gives you an early warning of changes in price direction.

The Accelerator Oscillator (AC) indicator value is fluctuating around 0(zero).

The Longer time frame signals are more accurate than short time frame.

Calculation --> The Accelerator Oscillator (AC) derived from the Awesome Oscillator (AO) indicator and it’s the current value of Awesome Oscillator (AO) minus the Simple Moving Average (SMA) of Awesome Oscillator (AO) over the most recent five intervals.