Volume Zone Oscillator

What is the Volume Zone Oscillator?

The Volume Zone Oscillator (VZO) is a bounded volume oscillator introduced by Walid Khalil and David Steckler in 2009. Each bar's volume is signed by close direction: positive when the close is above the prior close, negative when below. The VZO is the exponential moving average of that signed volume divided by the exponential moving average of total volume, multiplied by 100, so readings fall between -100 and +100; 14 periods is a widely used length.

As the name suggests, it is read in zones rather than by crossovers alone. The published guidance describes a bullish volume regime above roughly +5 and a bearish one below -5, with the ±40 area watched as overbought/oversold territory in ranging markets and ±60 as extreme. Because only the sign of the close-to-close change classifies volume, the VZO answers one narrow question, whether turnover is concentrating on up closes or down closes, and like any bounded oscillator its extremes can persist in trends.

How traders use it

• As a volume-regime filter: holding above the bullish boundary supports long setups and holding below the bearish boundary supports shorts, while readings oscillating around zero warn that neither side's volume dominates.
• As an extreme-fade tool in ranges: pushes toward ±40 and beyond are watched for reversion when the market is rangebound, while in trends the same extremes read better as strength, the familiar caveat with RSI extremes.
• As confirmation from a different input: the VZO's magnitude comes from volume, with price contributing only the sign, so its agreement with a price-based oscillator adds information in a way that stacking two price oscillators, which share inputs, does not.