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# StdDev

## Definition

Returns the standard deviation of the collection on a per unit basis.

## Property Value

A **double** value that represents the standard deviation of the collection on a per unit basis.

## Syntax

`\<tradecollection\>.TradesPerformance.\<tradesperformancevalues\>.StdDev`

## Examples

```csharp
protected override void OnBarUpdate()
{
     // Print out the standard deviation of all trades
     Print("Standard deviation of all trades is: " + SystemPerformance.AllTrades.TradesPerformance.Currency.StdDev);
}
```