Bandwidth is a metric used with Bollinger Bands. The bandwidth formula is the width between the top band and the lower band of the Bollinger Bands. This is a pretty important formula when following Bollinger Bands.
It is a pretty straight forward idea, the wider the bandwidth, the more volatile the stock is. The more narrow the bandwidth, the less volatile a stock is.
When a bandwidth gets really low you start getting the "squeeze" or the "pinch" signal. This usually signals that the stock will have a break out in volatility, with a dramatic up or down movement. The low bandwidth happens when a stocks price movement is very low day to day, with no extreme up or down. Making its volatility very low.
On the other hand, a large bandwidth indicates the stock has a high level of volatility. This usually indicates a breakout or a big downfall.
Stock Wolf Bandwidth indicators:
When seeing "*" with a Bandwidth number means the bandwidth has reached a 14 Day Low.
When seeing "**" with bandwidth means the bandwidth has reached a 14 Day High.