An upper band which is the n-period SMA plus K standard deviations, where K is a constant.
An lower band which is the n-period SMA minus K standard deviations, where K is a constant.
Bolliger Bands were developed by John Bollinger
Because standard deviation is a volatility measure, the two bands will contract when volatility is low and expand when volatility is high.
When the price curve touches or breaches the upper band this is as seen as a sell signal, since it is believed that the currency is overbought. When the price curve touches or breaches the lower band this is as seen as a buy signal, since it is believed that the currency is oversold.
This is for general information purposes only - Examples shown are for illustrative purposes and may not reflect current prices from OANDA. It is not investment advice or an inducement to trade. Past history is not an indication of future performance.
Trading FX and/or CFDs on margin is high risk and not suitable for everyone. Losses can exceed investment.