The McClellan Summation Index is a market breadth indicator which was developed by Sherman and Marian McClellan. It is based on the McClellan Oscillator
and add its values together, effectively running a total. The index goes up when the McClellan Oscillator is positive and goes down when it is negative. Signals can be derived from the index crossing the middle line (bullish when it's crossing up and bearish when it's crossing down). Other potential signals include divergences and overbought and oversold conditions. The indicator is best used in combination with other analysis techniques.