public void AddDrpNegativeAmount() { var stock = new Stock(Guid.NewGuid()); stock.List("ABC", "ABC Pty Ltd", new Date(1974, 01, 01), false, AssetCategory.AustralianStocks); var holding = new Holding(stock, new Date(2000, 01, 01)); holding.AddDrpAccountAmount(new Date(2001, 01, 01), 100.00m); holding.AddDrpAccountAmount(new Date(2002, 01, 01), -50.00m); holding.DrpAccount.Balance().Should().Be(50.00m); }