The Chaikin Oscillator is the Moving Average Convergence Divergence indicator (MACD) applied to the Accumulation/Distribution Line. A bullish signal happen when the price action develops a lower low into oversold zones and the oscillator diverges with a higher low and begins to rise. A bearish signal happen when the price action develops a higher high into overbought zones and the oscillator diverges with a lower high and begins to fall.
