The Positive Volume Index (PVI) attempts to identify bull markets. The PVI shows
what the uninformed investors are doing, while the Negative Volume Index shows what
the smart investors are doing. It is based on the assumption smart investors dominate
trading on light volume days and uninformed investors dominates trading on active
days. The PVI changes on days when the volume is up and stays flat on down volume
Also see the Negative Volume Index.
The Positive and Negative Volume Index were developed by Norman Fosback and are
described in his 1976 book, Stock Market Logic.