FOREX BOLLINGER BANDS
Bollinger bands expand during volatile times and contract during calmer periods. They are plotted directly on the forex price chart
Calmer periods in the forex market tend to precede more significant moves.
If the forex price moves outside the bands a continuation is expected to occur.
When the peaks break through the bands and soon afterwards peak inside the bands a reversal is expected to occur on the forex price. The same would happen with the bottoms.
When a move begins at one end of the bands it tends to move to the other end of the band effectively containing the forex price.