The McClellan Oscillator 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 was developed by Sherman
and Marian McClellan. Extensive coverage of the oscillator is provided
in their book Patterns for Profit.
Interpretation
Indicators that use advancing and declining issues
to determine the amount of participation in the movement of the stock
market are called "breadth" indicators. A healthy bull market is
accompanied by a large number of stocks making moderate upward advances
in price. A weakening bull market is characterized by a small number of
stocks making large advances in price, giving the false appearance that
all is well. This type of divergence often signals an end to the bull
market. A similar interpretation applies to market bottoms, where the
market index continues to decline while fewer stocks are declining.
The McClellan Oscillator is one of the most popular
breadth indicators (another popular breadth indicator is the
Advance/Decline Line). Buy signals are typically generated when the
McClellan Oscillator falls into the oversold area of -70 to -100 and
then turns up. Sell signals are generated when the oscillator rises into
the overbought area of +70 to +100 and then turns down.
If the oscillator goes beyond these areas (i.e.,
rises above +100 or falls below -100), it is a sign of an extremely
overbought or oversold condition. These extreme readings are usually a
sign of a continuation of the current trend.
For example, if the oscillator falls to -90 and
turns up, a buy signal is generated. However, if the oscillator falls
below -100, the market will probably trend lower during the next two or
three weeks. You should postpone buying until the oscillator makes a
series of rising bottoms or the market regains strength.
Example
The following chart illustrates the five "trading
zones" of the McClellan Oscillator (i.e., above +100, between +70 and
+100, between +70 and -70, between -70 and -100, and below -100).
This next chart shows the McClellan Oscillator and
the Dow Industrials.
drew "buy" arrows when the Oscillator rose above -70
and "sell" arrows when the Oscillator fell below +70. This indicator
does an excellent job of timing entry and exit points.
Calculation
The McClellan Oscillator is the difference between
10% (approximately 19-day) and 5% (approximately 39-day) exponential
moving averages of advancing minus declining issues.