When Volume Oscillator is above the Zero-Line, this signifies that the shorter-term volume moving average is above the longer-term volume moving average indicating the short term trend is higher than the longer-term volume trend.
When Volume Oscillator is below the Zero-Line, this signifies that the longer-term volume moving average is above the shorter-term volume moving average indicating the long term volume trend is higher than the short-term volume trend.
Calculation:
Volume Oscillator = 100 * SMASHR – SMALNG / SMALNG
Where:
SMASHR = Shorter Period SMA of Volume
SMALNG = Longer Period SMA of Volume