Bollinger BandWidth: the band spread as a percentage of the basis, so it is
comparable across instruments and across price levels.
The two companion plots are rolling extremes of the bandwidth itself, not
of price: they turn "is this narrow?" from a judgement call into a comparison
against the last N bars of the same series.
Bollinger BandWidth: the band spread as a percentage of the basis, so it is comparable across instruments and across price levels.
The two companion plots are rolling extremes of the bandwidth itself, not of price: they turn "is this narrow?" from a judgement call into a comparison against the last N bars of the same series.