Bollinger Bands are a technical analysis tool created by John Bollinger in the 1980s. The bands are used to gain insights into the price and volatility of a number of asset types, including currencies, stocks, and commodities. Bollinger Bands are supremely useful because they can help determine overbought/oversold levels, monitor breakouts, or be used as a trend following tool. On the chart Bollinger Bands consist of three lines. The middle line uses a simple moving average, and the upper and lower lines are placed two standard deviations away from the middle line.