Bitcoin's Daily Bollinger Bands Narrow to One of Tightest Widths in 2½ Years

On Oct. 20, Bitcoin (BTC)'s daily Bollinger Bands reached one of their tightest widths in 2½ years, reflecting subdued recent price swings without indicating where the market will move next.

Bollinger Bands place an upper and lower line around a central price average. They typically use a 20-day simple moving average for the middle line, with the outer lines set two standard deviations above and below it. Standard deviation measures how much prices vary from their average. When the gap between the outer lines narrows, recent prices have varied less.

Pronounced narrowing has often preceded a directional move. The pattern can be followed by a move up or down, so the Oct. 20 reading does not favor either direction. Band width measures recent variation; it does not set a price target or a timetable for a breakout.

The observation concerns Bitcoin's daily bands, whose typical calculation looks back 20 days. It describes the tightness of recent trading without identifying a level that Bitcoin must cross to confirm a new move.