' Excel for Windows. Needs VBA-JSON 2.3.1: import its JsonConverter.bas
' and tick Tools > References > Microsoft Scripting Runtime
Sub FundOverlap()
    ' Read both funds' files; each has the date of its own issuer's file
    Dim funds As Object, http As Object, t As Variant
    Set funds = CreateObject("Scripting.Dictionary")
    For Each t In Array("VOO", "QQQ")
        ' ServerXMLHTTP does not read the proxy set in Windows: behind a
        ' company proxy, create MSXML2.XMLHTTP.6.0 instead
        Set http = CreateObject("MSXML2.ServerXMLHTTP.6.0")
        http.Open "GET", "https://tickerinside.com/api/v1/fund/" _
            & LCase(t) & ".json", False
        http.setRequestHeader "User-Agent", _
            "MyProject/1.0 (+https://example.com)"
        http.send
        If http.Status <> 200 Then Err.Raise 513, , "HTTP " & http.Status
        Set funds(t) = JsonConverter.ParseJson(http.responseText)
        Debug.Print t & " holdings_as_of " & funds(t)("holdings_as_of")
    Next t

    ' Overlap by weight, as the site computes it: for every ticker both
    ' funds hold, add the smaller of its two weights
    Dim a As Object, b As Object, overlap As Double, inBoth As Long
    Set a = funds("VOO")("holdings")
    Set b = funds("QQQ")("holdings")
    For Each t In a.Keys
        If b.Exists(t) Then
            overlap = overlap + WorksheetFunction.Min(a(t), b(t))
            inBoth = inBoth + 1
        End If
    Next t
    Debug.Print "overlap by weight " & Format(overlap, "0.0") & "%, " _
        & inBoth & " companies in both"

    ' The lines to print under the figure, one per fund file
    Debug.Print funds("VOO")("cite_as")
    Debug.Print funds("QQQ")("cite_as")
End Sub