wpf listcollectionview grouping by multiple columns and calculating the amount and quantity

var collection = new List<Result>
{
    new Result {Name = "A", Security = "S1", Quantity = 5, Amount = 20},
    new Result {Name = "A", Security = "S2", Quantity = 5, Amount = 20},
    new Result {Name = "A", Security = "S3", Quantity = 5, Amount = 20},
    new Result {Name = "B", Security = "S1", Quantity = 5, Amount = 20},
    new Result {Name = "B", Security = "S2", Quantity = 5, Amount = 20},
    new Result {Name = "C", Security = "S1", Quantity = 5, Amount = 20},
    new Result {Name = "C", Security = "S2", Quantity = 5, Amount = 20},
    new Result {Name = "C", Security = "S3", Quantity = 5, Amount = 20},
};

var cvs = new CollectionViewSource { Source = collection };
cvs.GroupDescriptions.Add(new PropertyGroupDescription("Name"));
cvs.GroupDescriptions.Add