diff --git a/EvoCalculator.Core.Calculation/v3/Columns/PIColumn.cs b/EvoCalculator.Core.Calculation/v3/Columns/PIColumn.cs
index 60acfb1..8713a05 100644
--- a/EvoCalculator.Core.Calculation/v3/Columns/PIColumn.cs
+++ b/EvoCalculator.Core.Calculation/v3/Columns/PIColumn.cs
@@ -18,6 +18,6 @@ public class PIColumn : BaseColumnWithNPV
             Values[i] = NPV(cashflowMSFOWithCFColumn.Values.Skip(1).Take(i), preparedValues.LoanRate);
         }
 
-        Values[0] = Values[^1] / (cashflowMSFOColumn.GetValue(0) + cashflowMSFOColumn.GetValue(1));
+        Values[0] = -Values[^1] / (cashflowMSFOColumn.GetValue(0) + cashflowMSFOColumn.GetValue(1));
     }
 }
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