Trends/Volume and money flow

Negative volume index

A running index that changes only on days when volume is lower than the day before.

Volume and money flowBest on 1Y, 3YAlso called NVI

Illustration of the negative volume index shape. It is a sketch, not real price data.

What it shows

Paul Dysart's NVI starts at 1000. On days when volume is lower than yesterday, the index changes by the percent change in price. On days with higher volume, it stays the same.

The idea is to track what price does on quiet days. It is the counterpart of the positive volume index.

How we find it

The same code that draws it on your chart follows these steps, with the same result every time.

Start at 1000.
If volume < previous volume: NVI = NVI × (1 + percent price change).
Otherwise NVI is unchanged.
Plot under the price.

Starting values: Start 1000. These are proposed and will be tuned on real price data before launch.

How to read it

The panel shows the index.
It moves only on days with falling volume.
Flat stretches are days with rising volume.

Status labels you may see

Label	What it means
Rising	NVI above its value 20 bars ago.
Falling	Below its value 20 bars ago.
Above its 255-bar average	NVI above its long average.

What cancels it

Nothing cancels it.

What traders check next

Its long-term average.
Slope.
Price trend.

Limits

Based on the idea that quiet days reflect informed trading, which is an assumption.
Needs long history.
Rarely used.

Try it in forecastviz

Open any ticker and choose Volume and money flow → Negative volume index in the left menu.
Switch between 1Y, 3Y to see how the picture changes.
Compare with Volume price trend and On-balance volume on the same chart.

Open on a ticker

Questions

Why use quiet days?

One view is that large investors move on quiet days. It is a theory.

Is it proven?

We make no claim.