Subscript out of range error in a Sub procedure with ranges and arrays

I have written the following VBA Code, and at one point I place values from a Range (CoursAction) into an array(ValeursAction). Later on I use the values in the array to obtain a threshold value (Var). However, I get a "Subscript out of range" error though I think I have defined everything.

Or is it ValeursAction() As Variant that is incorrect? It is supposed to be an array... Or should I Re-dimension it? I am sorting it with Call Tri1(ValeursAction).

Option Explicit

Sub Performance()
Dim N As Long
Dim EnsembleActions As Range
Dim Nb_Actions As Integer
Dim Action As Range
Dim CoursAction As Range
Dim i As Integer
Dim SharpeRatio As Double
Dim TauxRf As Double
Dim RendsEcart As Double
Dim NomAction As String
Dim ValeursAction() As Variant
Dim NB As Integer

    With Worksheets("Actions")
        Nb_Actions = .Cells(1, Columns.Count).End(xlToLeft).Column
    End With

    With Worksheets("Actions")
        Set EnsembleActions = .Range(.Cells(2, 1), .Cells(.Rows.Count, Nb_Actions).End(xlUp))
    End With

    For Each Action In EnsembleActions.Columns
        i = i + 1
        Set CoursAction = Action

        TauxRf = Worksheets("Performance").Cells(2, 2).Value
        RendsEcart = WorksheetFunction.StDev(CoursAction)
        
         NB = WorksheetFunction.Count(CoursAction)
        
        'We place values from the range in a table
        With Worksheets("Actions")
            ValeursAction = .Range(.Cells(1, 1), .Cells(.Rows.Count, 1)).Value
        End With
        
        Call Tri1(ValeursAction)
        
       Dim alpha As Double
       Dim Var As Double
       
        alpha = Worksheets("Performance").Cells(3, 2).Value
        
        Var = ValeursAction(Int(NB * alpha))
        
    
        NomAction = Worksheets("Actions").Cells(1, i).Value

        With Worksheets("Performance")
            .Cells(4 + i, 1) = NomAction
         
            .Cells(4 + i, 2) = Var
            
        End With
    Next Action

End Sub

Sub Tri1(plaga As Variant)
Dim ligne_Deb As Long
Dim ligne_Fin As Long

    ligne_Deb = LBound(plaga)
    ligne_Fin = UBound(plaga)

    Dim i As Long, J As Long
    Dim tmp As Long

    For i = ligne_Deb To ligne_Fin - 1
        For J = ligne_Fin To i + 1 Step -1
            If plaga(J, 1) < plaga(J - 1, 1) Then
                tmp = plaga(J, 1)
                plaga(J, 1) = plaga(J - 1, 1)
                plaga(J - 1, 1) = tmp
            End If
        Next J
    Next i

End Sub

Hi

No, INT just takes the integer component of the number (for positive numbers). From the help file

Rounds a number down to the nearest integer

rylo