diff --git a/lib/trends/dema/Dema.cs b/lib/trends/dema/Dema.cs
index c93752e2..0bb9b9c5 100644
--- a/lib/trends/dema/Dema.cs
+++ b/lib/trends/dema/Dema.cs
@@ -123,8 +123,8 @@ public sealed class Dema : ITValuePublisher
         if (source.Count == 0) return new TSeries();
 
         int len = source.Count;
-        var t = new List<long>(len);
-        var v = new List<double>(len);
+        List<long> t = new(len);
+        List<double> v = new(len);
         CollectionsMarshal.SetCount(t, len);
         CollectionsMarshal.SetCount(v, len);
 
diff --git a/lib/trends/ema/Ema.cs b/lib/trends/ema/Ema.cs
index 6930ee9a..1f35351d 100644
--- a/lib/trends/ema/Ema.cs
+++ b/lib/trends/ema/Ema.cs
@@ -149,7 +149,7 @@ public sealed class Ema : ITValuePublisher
 
     public TSeries Update(TSeries source)
     {
-        if (source.Count == 0) return new TSeries();
+        if (source.Count == 0) return [];
 
         int len = source.Count;
         var t = new List<long>(len);
diff --git a/lib/trends/sma/Sma.cs b/lib/trends/sma/Sma.cs
index 37fa23ae..c06f42ba 100644
--- a/lib/trends/sma/Sma.cs
+++ b/lib/trends/sma/Sma.cs
@@ -137,7 +137,7 @@ public sealed class Sma : ITValuePublisher
 
     public TSeries Update(TSeries source)
     {
-        if (source.Count == 0) return new TSeries();
+        if (source.Count == 0) return [];
 
         int len = source.Count;
         var t = new List<long>(len);
diff --git a/lib/trends/t3/T3.cs b/lib/trends/t3/T3.cs
index 462abf1d..10d05d6d 100644
--- a/lib/trends/t3/T3.cs
+++ b/lib/trends/t3/T3.cs
@@ -172,7 +172,7 @@ public sealed class T3 : ITValuePublisher
 
     public TSeries Update(TSeries source)
     {
-        if (source.Count == 0) return new TSeries();
+        if (source.Count == 0) return [];
 
         int len = source.Count;
         var t = new List<long>(len);
diff --git a/lib/trends/tema/Tema.cs b/lib/trends/tema/Tema.cs
index 28f51a0c..51dd6aee 100644
--- a/lib/trends/tema/Tema.cs
+++ b/lib/trends/tema/Tema.cs
@@ -132,8 +132,8 @@ public sealed class Tema : ITValuePublisher
         if (source.Count == 0) return new TSeries();
 
         int len = source.Count;
-        var t = new List<long>(len);
-        var v = new List<double>(len);
+        List<long> t = new(len);
+        List<double> v = new(len);
         CollectionsMarshal.SetCount(t, len);
         CollectionsMarshal.SetCount(v, len);
 
diff --git a/lib/trends/trima/Trima.cs b/lib/trends/trima/Trima.cs
index 0c2d0b12..81c455be 100644
--- a/lib/trends/trima/Trima.cs
+++ b/lib/trends/trima/Trima.cs
@@ -144,8 +144,8 @@ public sealed class Trima : ITValuePublisher
         if (source.Count == 0) return new TSeries();
 
         int len = source.Count;
-        var t = new List<long>(len);
-        var v = new List<double>(len);
+        List<long> t = new(len);
+        List<double> v = new(len);
         CollectionsMarshal.SetCount(t, len);
         CollectionsMarshal.SetCount(v, len);
 
diff --git a/lib/trends/wma/Wma.cs b/lib/trends/wma/Wma.cs
index 5b8eedd8..d1720be8 100644
--- a/lib/trends/wma/Wma.cs
+++ b/lib/trends/wma/Wma.cs
@@ -144,8 +144,8 @@ public sealed class Wma : ITValuePublisher
         if (source.Count == 0) return new TSeries();
 
         int len = source.Count;
-        var t = new List<long>(len);
-        var v = new List<double>(len);
+        List<long> t = new(len);
+        List<double> v = new(len);
         CollectionsMarshal.SetCount(t, len);
         CollectionsMarshal.SetCount(v, len);
 
diff --git a/test_collection_expr.cs b/test_collection_expr.cs
new file mode 100644
index 00000000..72d08685
--- /dev/null
+++ b/test_collection_expr.cs
@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using QuanTAlib;
+
+public class Test
+{
+    public TSeries Create()
+    {
+        return [];
+    }
+}