---
url: /indicators/pvo.md
description: >-
  The Percentage Volume Oscillator is a simple oscillator view of the rate of
  change between two converging / diverging exponential moving averages of
  Volume.  It is presented similarly to MACD.
package: FacioQuo.Stock.Indicators
docs_version: v3
canonical: https://dotnet.stockindicators.dev/indicators/pvo
generated: 2026-09-30T04:41:06.055Z
commit: ae1f432eaa0b03ae9f39e032c69434b557efa4a2
---

# Percentage Volume Oscillator (PVO)

The [Percentage Volume Oscillator](https://www.google.com/search?q=Percentage+Volume+Oscillator+\(PVO\)) is a simple oscillator view of the rate of change between two converging / diverging exponential moving averages of Volume.
[\[Discuss\] 💬](https://github.com/facioquo/stock-indicators-dotnet/discussions/305 "Community discussion about this indicator")

```csharp
// C# usage syntax
IReadOnlyList<PvoResult> results =
  bars.ToPvo(fastPeriods, slowPeriods, signalPeriods);
```

## Parameters

| param | type | description |
| ----- | ---- | ----------- |
| `fastPeriods` | *`int`* | Number of periods (`F`) for the faster moving average.  Must be greater than 0.  Default is 12. |
| `slowPeriods` | *`int`* | Number of periods (`S`) for the slower moving average.  Must be greater than `fastPeriods`.  Default is 26. |
| `signalPeriods` | *`int`* | Number of periods (`P`) for the moving average of PVO.  Must be greater than or equal to 0.  Default is 9. |

### Historical price bars requirements

You must have at least `2×(S+P)` or `S+P+100` worth of `bars`, whichever is more, to cover the [warmup and convergence](https://github.com/facioquo/stock-indicators-dotnet/discussions/688) periods.  Since this uses a smoothing technique, we recommend you use at least `S+P+250` data points prior to the intended usage date for better precision.

`bars` is a collection of generic `TBar` historical price bars.  It should have a consistent frequency (day, hour, minute, etc).  See [the Guide](/guide/getting-started.md#historical-bars) for more information.

## Response

```csharp
IReadOnlyList<PvoResult>
```

* This method returns a time series of all available indicator values for the `bars` provided.
* It always returns the same number of elements as there are in the historical price bars.
* It does not return a single incremental indicator value.
* The first `S-1` slow periods will have `null` values since there's not enough data to calculate.

> [!WARNING]
> **🚩 ⚞ Convergence warning**
>
> The first `S+P+250` periods will have decreasing magnitude, convergence-related precision errors that can be as high as ~5% deviation in indicator values for earlier periods.

### `PvoResult`

| property | type | description |
| -------- | ---- | ----------- |
| `Timestamp` | *`DateTime`* | Date from evaluated `TBar` |
| `Pvo` | *`double`* | Normalized difference between two Volume moving averages |
| `Signal` | *`double`* | Moving average of the `Pvo` line |
| `Histogram` | *`double`* | Gap between the `Pvo` and `Signal` line |

### Utilities

* [.Condense()](/utilities/results.md#condense)
* [.Find(lookupDate)](/utilities/results.md#find-by-date)
* [.RemoveWarmupPeriods()](/utilities/results.md#remove-warmup-periods)
* [.RemoveWarmupPeriods(removePeriods)](/utilities/results.md#remove-warmup-periods)

See [Utilities and helpers](/utilities.md) for more information.

## Chaining

Results can be further processed on `Pvo` with additional chain-enabled indicators.

```csharp
// example
var results = bars
    .ToPvo(..)
    .ToSlope(..);
```

This indicator must be generated from `bars` and **cannot** be generated from results of another chain-enabled indicator or method.

See [Chaining indicators](/guide/chaining.md) for more.

## Streaming

Use the buffer-style `List<T>` when you need incremental calculations without a hub:

```csharp
PvoList pvoList = new(fastPeriods, slowPeriods, signalPeriods);

foreach (IBar bar in bars)  // simulating stream
{
  pvoList.Add(bar);
}

// based on `ICollection<PvoResult>`
IReadOnlyList<PvoResult> results = pvoList;
```

Subscribe to a `BarHub` for advanced streaming scenarios:

```csharp
BarHub barHub = new();
PvoHub observer = barHub.ToPvoHub(fastPeriods, slowPeriods, signalPeriods);

foreach (IBar bar in bars)  // simulating stream
{
  barHub.Add(bar);
}

IReadOnlyList<PvoResult> results = observer.Results;
```

See [Buffer lists](/guide/styles/buffer.md) and [Stream hubs](/guide/styles/stream.md) for full usage guides.