Bollinger bands, were developed by John Bollinger and generally are calculated by plotting two standard deviations above and two standard deviations below a 20-period moving average.

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Bollinger bands are used by traders in many different ways, and John Bollinger himself has his own set of rules and guidelines, which can be found on his Web site, BollingerBands.com.

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"With ETFs the individual investor has tools and techniques that were solely the province of sophisticated investors even a year ago, " says John Bollinger of Bollinger Capital Management, whose Bollinger Bands are a popular method for identifying stocks that have moved outside their normal trading pattern.

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