Simple Master-Detail Databinding

In WPF, Listbox can hold IEnumerable while ContentPresneter can display CurrentItem. When both control share the same DataContext, Master detail relationship is established:

    public class Stocks : List
    {
        public Stocks()
        {
            Add(new Stock("YHOO", 27.90));
            Add(new Stock("MSFT", 28.90));
            Add(new Stock("GOOG", 179.40));
        }
    }

    public class Stock {
        public string Symbol { get; set; } 
        public double Price { get; set; } 
        public Stock(string s, double p) { 
            this.Price = p; this.Symbol = s; }
        public override string ToString() { ..} 
    }


<Window x:Class="MasterDetailWPF.Window1"
    xmlns="..."
    xmlns:x="..."
    ...
        xmlns:local="clr-namespace:MasterDetailWPF">
    <Window.DataContext>
        <local:Stocks>
    </Window.DataContext>
    <Grid>
        <ListBox .. 
                 ItemsSource="{Binding}"
                  IsSynchronizedWithCurrentItem="True">
            
        </ListBox>
        <ContentPresenter Content="{Binding}" ..>
            <ContentPresenter.ContentTemplate>
                
                <DataTemplate>
                    <TextBox Text="{Binding Path=Symbol, Mode=Default}" /> 
                </DataTemplate>
            </ContentPresenter.ContentTemplate>
        </ContentPresenter>
    </Grid>
</Window>