On balance volume
Granville's on balance volume indicator is a great indicator and can almost be
used by itself, although this is not really recommended. It works on the premise
that rather large commercial traders accumulate or disperse the commodity in
volume prior to a corresponded move in price. That is, a change in volume will
precede a potential change in the trend.
On Balance Volume is a running total, volume indicator that is arrived at by
adding or subtracting the day's volume, depending on whether the closing price
is higher or lower than the previous close. If the close is higher then the
volume is added and if the close is lower the volume is subtracted. It requires
about 40 data points before a meaningful signal can be generated.
On Balance Volume OBV = Previous Days OBV + today's volume (if the closing
price is higher)
OBV = Previous Days OBV - today's volume (if the closing price is lower)
How to use
If the market is trading in a range the indicator is likely to also reflect
that by remaining in its own range, however the indicator will often breakdown
or breakout from its own range prior to price breaking down or breaking out
from its range. Therefore the simplest application of Granville's On Balance
Volume Indicator is to buy when the indicator breaks out from its recent range
and sell when it breaks down from its range. It might take price a day or even
two to confirm the move, so patience and other supporting trend change indicators
will help.
If the market is currently trending then the indicator can be used to confirm
the continuation of the trend or alert to a potential change in trend. Divergence
between price and the indicator can be used to signal a potential change in
trend. That is, if the OBV is rising while price is falling then the move is
unlikely to continue. Conversely, if the OBV is falling while price is rising,
the up move is likely to fail.
In the example below you can see that the OBV broke out of its range just prior
to price breaking out and then gapping higher. You will also notice that each
time the OBV has moved to a new high, price has followed shortly after, which
is to be expected as both price and the indicator are moving in an up trend.

© Copyright
2003 CQG, Inc. All rights reserved worldwide
Disclaimer
© The MacLean Group Pty Ltd ACN 096 967 038. All rights reserved 2003. This article
has been prepared by The MacLean Group and licensed to ASX. The views are those
of the author and not of ASX. This material is educational and it is not intended
to constitute financial advice.

