Bollinger Bands

Bollinger Bands are a technical analysis tool invented by John Bollinger in the 1980s. Having evolved from the concept of trading bands, Bollinger Bands can be used to measure the highness or lowness of the price relative to previous trades.Bollinger Bands consist of:a middle band being a N-period simple moving averagean upper band at K times a N-period standard deviation above the middle banda lower band at K times a N-period standard deviation below the middle bandTypical values for N and K are 20 and 2, respectively.
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