D07-F07-A01 · LEVEL 2 GUIDED LAB · SYNTHETIC DATA

Bollinger %B

Where does price sit relative to the two Bollinger boundaries? Walk the evidence clock one stage at a time. This lab teaches the publication contract; it does not simulate returns, platform parity, or trade performance.

Selected expression

%B=(P-lower)/(upper-lower); upper=MA+k sigma; lower=MA-k sigma

Availability rule

An output at t may use only finite, basis-consistent observations available through t; chart alignment never moves the information clock backward.

calculated · step 1 of 7

Verified synthetic fixture

This lab is paired with datasets/implementation-fixtures.json: 96 deterministic, oldest-to-newest observations spanning oscillating, rising, and moderating regimes. It is teaching data—not market history or predictive evidence.

Canonical latest output (D07-F07-A01)
{
  "center": 104.20055051999998,
  "upper": 108.52982269312228,
  "lower": 99.87127834687767,
  "percent_b": 0.013805568042643967
}

Executable checks cover this result, flat/zero-volume boundaries, invalid timestamps, and prefix causality in both language entry points.