+1  A: 

Try binding your DataGrid's SelectedItem to a property in your viewmodel.

You can then access this property in your OpenTradeHistory() method.

Veer
I'm not sure if Right click on the XamDataGrid row selects the record as a SelectedItem. And this doesn't really solve the issue as I'm trying to pass a parameter from the Command that handles the right click > context Menu on the XamDataGrid.
@saddaypally: What is meant by SelectedItems in this line `CommandParameter="{Binding Path=SelectedItems}">` ? If those were the original Selected Items in the grid then why do you send them as a parameter, if right click doesn't select an item?
Veer
@Veer, Thanks for coming back on this. I didn't find a SelectedItem property on XamDataGrid, all I found was this and I thought, I could use this and iterate over the items myself when I'm able to get a hold of it. I actually need to be able to pass the values from Row on which I right click on and open a ContextMenu Item to view details about that item from the Grid. does that make it clear? Any help, appreciated.