Bollinger Bands are used on trader’s graphs as indicators to demonstrate market volatility. The bands incorporate a moving average line and two standard deviation lines. To analyse the trade movements using the Bollinger Bands, you have to see whether they are converging or diverging. A convergence suggests a reduction in volatility and a divergence suggests that an asset has become volatile, and is therefore likely to move price. They are important factors to assess in gaining an entry. You should include them on your trading graphs to check to see if the time is right for your trade.
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