Bollinger Bands
John Bollinger · 1980s
What it measures
A corridor two standard deviations either side of the 20-day average, showing where inside it price is travelling. A narrowing corridor — a squeeze — is read as a warning that a large move is coming.
How TickTurn reads it
We use the position inside the corridor (%B). Dropping through the lower band (under 0.05) counts bullish in expectation of a snap-back; punching through the upper band (over 0.95) counts bearish. Inside, above 0.6 is bullish and below 0.4 is bearish.
That judgement is made on closed daily bars only; a bar still in progress is left out, because including it makes the same symbol change its answer within the day. On the result screen this indicator holds one vote out of 21.
It is not an answer on its own
If one indicator could call tomorrow, everyone would use only that one. TickTurn asks 21 of them together not because any single one is trusted, but to show plainly where they disagree. Even the combined score, measured against the right baseline, came out only a shade better than chance — the scoring is written up in how we tested.