What is a Bollinger Band squeeze?
A Bollinger Band squeeze occurs when the bands contract to an unusually narrow range, indicating low volatility. This often precedes a directional breakout — once the squeeze ends, price tends to move sharply in one direction. The Bollinger-inside-Keltner squeeze is one of the most popular volatility breakout setups.
More detail
Squeeze duration matters: longer squeezes often precede larger breakouts.
The breakout direction isn't predictable from the squeeze alone — wait for the actual break with volume confirmation.
John Bollinger himself estimates squeezes correctly predict the breakout direction only about 50% of the time — they're volatility setups, not direction predictions.