diff --git a/src/a-d/Beta/Beta.Api.cs b/src/a-d/Beta/Beta.Api.cs
index 9bc53ed65..34d379e79 100644
--- a/src/a-d/Beta/Beta.Api.cs
+++ b/src/a-d/Beta/Beta.Api.cs
@@ -37,7 +37,7 @@ public static IEnumerable<BetaResult> GetBeta(
             = mrktResults.ToTuple();
 
         return CalcBeta(tpListEval, tpListMrkt, lookbackPeriods, type)
-            .SyncIndex(evalResults);
+            .SyncIndex(evalResults, SyncType.Prepend);
     }
 
     // SERIES, from TUPLE
diff --git a/src/a-d/Correlation/Correlation.Api.cs b/src/a-d/Correlation/Correlation.Api.cs
index aa696c4db..709e77697 100644
--- a/src/a-d/Correlation/Correlation.Api.cs
+++ b/src/a-d/Correlation/Correlation.Api.cs
@@ -34,7 +34,7 @@ public static IEnumerable<CorrResult> GetCorrelation(
             = quotesB.ToTuple();
 
         return CalcCorrelation(tpListA, tpListB, lookbackPeriods)
-            .SyncIndex(quotesA);
+            .SyncIndex(quotesA, SyncType.Prepend);
     }
 
     // SERIES, from TUPLE
diff --git a/src/m-r/Prs/Prs.Api.cs b/src/m-r/Prs/Prs.Api.cs
index 11a11afae..16bd36901 100644
--- a/src/m-r/Prs/Prs.Api.cs
+++ b/src/m-r/Prs/Prs.Api.cs
@@ -35,7 +35,7 @@ public static IEnumerable<PrsResult> GetPrs(
             = quotesBase.ToTuple();
 
         return CalcPrs(tpListEval, tpListBase, lookbackPeriods, smaPeriods)
-            .SyncIndex(quotesEval);
+            .SyncIndex(quotesEval, SyncType.Prepend);
     }
 
     // SERIES, from TUPLE