Negative volume index

Conditionally accumulate price or breadth changes only on sessions whose trading volume falls from the previous session, producing a path-dependent technical-analysis series whose interpretation requires a declared variant and test period.

Version

v2 · 2026-08-30 · History

Domain-specific #

2360

Origin domain

technical analysis

Subdomain

conditional cumulative market indicators

Core Idea

In the common Fosback form, the Negative Volume Index is a cumulative series that updates only when (V_t<V_{t-1}): (NVI_t=NVI_{t-1}(1+(C_t-C_{t-1})/C_{t-1})); otherwise (NVI_t=NVI_{t-1}). Dysart's earlier breadth version accumulates advances minus declines on lower-volume sessions. A binary gate selects lower-volume sessions and compounds or accumulates the chosen market change only on those dates, preserving the entire selected-path history; a later interpretation may compare the series with its own moving average, but that signaling layer is separate from the index recurrence.

Scope of Application

Negative volume index applies when the analyst can specify an ordered market time series with comparable closing-price or breadth observations and trading-volume observations for consecutive sessions and establish that the series has a declared base and variant, changes only on sessions satisfying the lower-volume gate, and updates by the corresponding price-return or market-breadth rule in chronological order. This entry is descriptive financial reference material, not investment advice. It defines historical indicator variants but makes no claim that NVI predicts returns, identifies informed trading, or remains profitable in any present market.

Clarity

A clear claim names the carrier, governing rule, assumptions, and recognition test. This matters because negative refers to the direction of the volume comparison rather than a negative index value or price return, and modern sources often call only Fosback's revision NVI while attributing it loosely to Dysart.

Manages Complexity

The abstraction compresses Dysart advance–decline and Fosback price-return versions, daily and weekly sampling, broad indexes and improperly extrapolated single-security uses, alternative base levels, moving-average overlays, raw and adjusted market data, and different equal-volume conventions into a stable carrier, rule, invariant, and failure boundary. It makes comparison tractable while retaining the variables that control validity.

Abstract Reasoning

1. Type the carrier. Establish an ordered market time series with comparable closing-price or breadth observations and trading-volume observations for consecutive sessions and reject examples from a different problem. 2. Lock the rule. Express that the series has a declared base and variant, changes only on sessions satisfying the lower-volume gate, and updates by the corresponding price-return or market-breadth rule in chronological order independently of one notation or implementation.

Knowledge Transfer

Transfer within technical analysis is strong when new cases preserve the same carrier, mechanism, and diagnostic. The move from Starting from 1000, a Fosback NVI rises by the market's percentage return on a session with lower volume than the day before and remains unchanged on the next session if volume rises to An analyst compares NVI behavior above and below a one-year moving average in a predeclared historical sample, then tests the same rule on later unseen data with transaction costs and benchmark alternatives demonstrates that continuity.

Relationships to Other Abstractions

Current abstraction Negative volume index Domain-specific

Parents (1) — more general patterns this builds on

• Negative volume index is a kind of Accumulation Prime

  The proposed strict upward parent is prime:accumulation.

Hierarchy path (1) — routes to 1 parentless root

• Negative volume index → Accumulation

Neighborhood in Abstraction Space

Negative volume index sits in a sparse region of the domain-specific corpus (67^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Financial Risk & Market Indicators (29 abstractions)

Nearest neighbors

• True strength index — 0.85
• Williams %R — 0.85
• Technical analysis — 0.85
• Name your own price — 0.85
• Making-up price — 0.84

Computed from structural-signature embeddings · 2026-09-08