diff --git a/Model/ModelPerformanceAggregator.cs b/Model/ModelPerformanceAggregator.cs
index a3e2f68..2c066c8 100644
--- a/Model/ModelPerformanceAggregator.cs
+++ b/Model/ModelPerformanceAggregator.cs
@@ -1,4 +1,5 @@
-using MarketData.Cache;
+using MarketData;
+using MarketData.Cache;
 using MarketData.DataAccess;
 using MarketData.MarketDataModel;
 using MarketData.Utils;
@@ -78,6 +79,11 @@ namespace TradeBlotter.Model
               LocalPriceCache.GetInstance().Add(prices);
             }
             Price price=LocalPriceCache.GetInstance().GetPrice(openPosition.Symbol,currentDate);
+            if(null==price)
+            {
+              MDTrace.WriteLine(LogLevel.DEBUG,String.Format("GetModelPerformance: No price for {0} on {1}",openPosition.Symbol,currentDate.ToShortDateString()));
+              continue;
+            }
             gainLoss+=((price.Close*openPosition.Shares)-(openPosition.PurchasePrice*openPosition.Shares));
             marketValue+=(price.Close*openPosition.Shares);
           }
@@ -311,6 +317,11 @@ namespace TradeBlotter.Model
               LocalPriceCache.GetInstance().Add(prices);
             }
             Price price=LocalPriceCache.GetInstance().GetPrice(openPosition.Symbol,currentDate);
+            if(null==price)
+            {
+              MDTrace.WriteLine(LogLevel.DEBUG,String.Format("GetModelPerformance: No price for {0} on {1}",openPosition.Symbol,currentDate.ToShortDateString()));
+              continue;
+            }
             gainLoss+=((price.Close*openPosition.Shares)-(openPosition.PurchasePrice*openPosition.Shares));
             marketValue+=(price.Close*openPosition.Shares);
           }
@@ -420,6 +431,11 @@ namespace TradeBlotter.Model
               LocalPriceCache.GetInstance().Add(prices);
             }
             Price price=LocalPriceCache.GetInstance().GetPrice(openPosition.Symbol,currentDate);
+            if(null==price)
+            {
+              MDTrace.WriteLine(LogLevel.DEBUG,String.Format("GetModelPerformance: No price for {0} on {1}",openPosition.Symbol,currentDate.ToShortDateString()));
+              continue;
+            }
             gainLoss+=((price.Close*openPosition.Shares)-(openPosition.PurchasePrice*openPosition.Shares));
             marketValue+=(price.Close*openPosition.Shares);
           }