Advance-Decline Indicator

The Advance-Decline Indicator is a market breadth indicator
based on the smoothed difference between advancing and declining issues.
The indicator shows when the stock market is overbought (and a correction
is due) and when it is oversold (and a rally is due).
The Advance-Decline Indicator is a 10-period exponential moving average of
the difference between the number of advancing and declining issues.