What is it?
The Percentage Volume Oscillator (PVO) shows the momentum of volume.
It measures the difference between two volume based moving averages as a percentage of the larger moving average.
How is it calculated?
Percentage Volume Oscillator = ((12 day EMA of volume – 26 day EMA of volume)/12 day EMA of volume) x 100
- Calculate the 12 day exponential moving average of volume and subtract the 26 day exponential moving average of volume from it
- Divide by the 12 day exponential moving average
- Multiple by 100
The Signal Line is usually a 9 day EMA of PVO.
The Histogram is usually PVO minus the Signal Line.
How do you read it?
The PVO can be used to confirm a price breakout. For example if price breaks through resistance and PVO is rising it confirms, or backs up, the break out. An upwards break on increasing volume has more credibility than a break on low volume as it shows there is increasing buyer enthusiasm behind it. Likewise, if price breaks resistance, but PVO is falling then it would warrant caution.
- Like the MACD indicator the PVO is shown with a signal line, a histogram and a centreline.
- Volume does not trend very well, so the PVO can be choppy.
- PVO bullish and bearish divergences do not provide very good signals.
- The PVO may not always move in sync with price action; the indicator is based on moving averages and as a result there can be lag between the PVO and price.
When the shorter volume EMA is above the longer volume EMA the PVO is positive and indicates volume levels are increasing.
When the shorter volume EMA is below the longer volume EMA the PVO is negative and indicates volume levels are decreasing.
In the example below we can see price broke upwards out of a symmetrical triangle. The histogram and PVO show volume declining in February. In mid March, approximately six weeks before the breakout, PVO turned up. Of note we can see the day before breakout the PVO crossed over into positive territory and then surged to 15 on the day of breakout. This meant the 12-day Volume EMA crossed above the 26-day EMA, volume was increasing rapidly and there were a lot of buyers behind the breakout.