McClellan Oscillator

 The McClellan Oscillator, developed by Sherman and Marian McClellan, is a market breadth indicator that is based on the smoothed difference between the number of advancing and declining issues on the New York Stock Exchange. The McClellan Oscillator is one of the most popular breadth indicators. Buy signals are typically generated when the McClellan Oscillator falls into the oversold area of -70 to -100 and turns up. Sell signals are generated when the oscillator rises into the overbought area of +70 to +100 and then turns down.

 Extensive coverage of the McClellan Oscillator is provided in their book Patterns for Profit.