D07-F05-A10 · LEVEL 2 GUIDED LAB · SYNTHETIC DATA

Negative Volume Index

How does a seeded index evolve only on lower-volume observations? 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

if V_t<V_(t-1): NVI_t=NVI_(t-1)*(1+return_t); else NVI_t=NVI_(t-1)

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-F05-A10)
{
  "value": 991.0425084378837
}

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