---
id: "P:cAlgo.API.AspSymbolChangedEventArgs.OldSymbol"
kind: "property"
type: "T:cAlgo.API.AspSymbolChangedEventArgs"
url: "https://help.ctrader.com/ctrader-algo/references/EventArgs/AspSymbolChangedEventArgs/OldSymbol/"
---

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

# AspSymbolChangedEventArgs.OldSymbol

Member of [AspSymbolChangedEventArgs](https://help.ctrader.com/ctrader-algo/references/EventArgs/AspSymbolChangedEventArgs/index.md).

## OldSymbol

Old symbol of active symbol panel.

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.

C#:

```csharp
public Symbol OldSymbol {get;}
```

Python:

```python
aspSymbolChangedEventArgs.OldSymbol: Symbol
```

### Returns

`Symbol` — 

### Examples

C#:

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

private void OnAspSymbolChanged(AspSymbolChangedEventArgs args)
{
    if (args.OldSymbol != null)
        Print("Previous symbol: {0}, bid: {1}", args.OldSymbol.Name, args.OldSymbol.Bid);
}
```

Python:

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

def on_asp_symbol_changed(self, args):
    if args.OldSymbol is not None:
        api.Print(f"Previous symbol: {args.OldSymbol.Name}, bid: {args.OldSymbol.Bid}")
```