Negative Volume Index

Negative Volume Index isolates what price does when the crowd goes quiet. The Negative Volume Index is a cumulative line that moves only on bars whose volume prints below the prior bar's, compounding by that session's percentage close-to-close change; equal- or rising-volume sessions leave it flat. The line seeds at an arbitrary 1000 — the absolute level carries no information — and is read through its slope and its standing relative to a long EMA of itself, the conventional one-year signal. The build colors the line by that regime, fills the gap to the average with a gradient, and alerts on both crosses.

How to Trade the Negative Volume Index?

• NVI above its signal EMA: quiet-session price behavior supports the primary trend — the classic constructive configuration.
• NVI below its signal EMA: quiet days lean toward distribution, the caution regime.
• Signal crosses: the Bullish and Bearish Signal Cross alerts mark regime changes; they are infrequent by design.
• Gradient depth: the fill strengthens with the distance between line and average, so the conviction of the current regime reads at a glance.

This is deliberately a slow instrument: it describes the backdrop and is not meant to time entries on its own.

Negative Volume Index Settings

• Base Level (default 1000): seed of the cumulative line; only sets the scale of the numbers.
• Signal EMA (default on, length 255): the conventional one-trading-year average. Hiding it removes only the plotted overlay — coloring, fill, and alerts still use it.
• Line Coloring (default Position vs Average): regime coloring, or a single neutral color.
• Gradient Fill (default on): the regime fill between line and average.
• Color inputs set the bullish, bearish, neutral, and signal EMA colors.

Frequently Asked Questions

How does NVI relate to the Positive Volume Index?

They partition the tape: NVI accumulates price change only on falling-volume sessions, while the Positive Volume Index does so only on rising-volume ones. Running both against their averages shows whether the quiet-day cohort and the loud-day crowd agree.

Why is the signal EMA 255 periods?

That is one trading year of daily sessions, the horizon the classic signal was defined on. On other timeframes the input still means 255 bars, so adjust it deliberately if you want the same one-year meaning elsewhere.

What data does it need?

A genuine volume feed — without one no session can register falling volume, and the script raises an error rather than plotting a flat line. Comparisons are also most meaningful on liquid symbols where turnover differences reflect participation rather than noise.