The Upside-Downside Volume indicator shows the
difference between up (advancing) and down (declining) volume on the New
York Stock Exchange. Click here for more information on Advancing,
declining, and unchanged volume.
Interpretation
The Upside-Downside Volume indicator shows the net
flow of volume into or out of the market. A reading of +40 indicates
that up volume exceeded down volume by 40 million shares. Likewise a
reading of -40 would indicate that down volume exceeded up volume by 40
million shares.
The indicator is useful to compare today's volume
action with previous days. Currently, normal readings are in the area of
50. Very active days exceed 150 million shares (the October, 1987 crash
reached -602).
The Cumulative Volume Index is a cumulative total of
the Upside-Downside Volume indicator.
Example
The following chart shows the Dow Jones Industrial
Average and the Upside-Downside Volume indicator.
I labeled the DJIA with "buy" arrows when the
Upside-Downside Volume indicator was greater than 200 and with "sell"
arrows when the indicator was less than -200.
Calculation
The Upside-Downside Volume indicator is calculated
by subtracting the daily volume of advancing stocks by the daily volume
of declining stocks.