GlossaryAdvanced
Negative Volume Index and Positive Volume Index (NVI and PVI)
Cumulative indicators that track price change specifically on days when volume falls (NVI) or rises (PVI) from the prior day.
The Negative Volume Index (NVI) and Positive Volume Index (PVI) are cumulative indicators that only update on specific days: NVI updates on days when trading volume is lower than the prior day, and PVI updates on days when volume is higher — each tracking the cumulative price change specifically during those respective days.
The underlying premise, originating with early market technicians, is that so-called "smart money" tends to trade more on quieter, lower-volume days, making NVI the more closely watched of the two historically, while PVI is read as reflecting broader, crowd-driven activity.
Examples
- NVI only changes on days when volume falls from the prior day — on every other day, it simply carries its prior value forward unchanged.
- NVI has historically received more analytical attention than PVI, based on the premise that lower-volume days better reflect informed trading activity.