---
id: "T:cAlgo.API.AspSymbolChangedEventArgs"
kind: "class"
namespace: "cAlgo.API"
url: "https://help.ctrader.com/ctrader-algo/references/EventArgs/AspSymbolChangedEventArgs/"
---

> Documentation index for agents: https://help.ctrader.com/ctrader-algo/llms.txt · machine index: https://help.ctrader.com/ctrader-algo/api.json

# AspSymbolChangedEventArgs (class)

Provides data for active symbol panel symbol changed event.

Environments: Desktop supported · CLI not supported · Cloud not supported.

- CLI: Available to plugins only, and plugins cannot run in the CLI.
- Cloud: Available to plugins only, and plugins cannot run in the cloud.

## Definition

```csharp
public class AspSymbolChangedEventArgs
```

## Examples

C#:

```csharp
protected override void OnStart()
{
    Asp.SymbolTab.SymbolChanged += OnAspSymbolChanged;
}

private void OnAspSymbolChanged(AspSymbolChangedEventArgs args)
{
    var oldSymbolName = args.OldSymbol?.Name ?? "none";
    Print("Active symbol panel symbol changed from {0} to {1}", oldSymbolName, args.NewSymbol.Name);
}
```

Python:

```python
def on_start(self):
    api.Asp.SymbolTab.SymbolChanged += self.on_asp_symbol_changed

def on_asp_symbol_changed(self, args):
    old_symbol_name = args.OldSymbol.Name if args.OldSymbol is not None else "none"
    api.Print(f"Active symbol panel symbol changed from {old_symbol_name} to {args.NewSymbol.Name}")
```

## Properties

- `public Symbol NewSymbol {get;}` — New symbol of active symbol panel. [details](https://help.ctrader.com/ctrader-algo/references/EventArgs/AspSymbolChangedEventArgs/NewSymbol/index.md)
- `public Symbol OldSymbol {get;}` — Old symbol of active symbol panel. [details](https://help.ctrader.com/ctrader-algo/references/EventArgs/AspSymbolChangedEventArgs/OldSymbol/index.md)