Breadth Advance/Decline Indicator

The Breadth Advance/Decline Indicator (also known as the Zweig AD Line) was developed by Martin Zweig. It allows analyzing the strength with which a market evolves.

Calculation Method

For a given market, it represents the moving average over a certain period (typically 10 days) of the following ratio:

R = Number of advancing stocks / (Number of declining stocks + Number of advancing stocks)

Example

Interpretation

Exceeding the 65% level generally corresponds to a bullish signal.
Below the 35% level, it is a bearish signal.

The trend of the Breadth Advance/Decline Indicator is also an effective indicator of the same nature as the AD Line Cumulative indicator.