Trend line in line chart next to input line chart
<p>I cannot figure out why a trend is drawn next to input serie chart. The trend curve should be plotted through the existing data (first serie) and extend 1 month ahead. Instead, it starts where the input serie ends and continues (see the orange dashed line):</p>

<p><a href="https://i.stack.imgur.com/AycA7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AycA7.png" alt="enter image description here"></a></p>

<p>The code I use for creating the trend line is following</p>

<pre><code>' do stuff for series (0) and (1)....
' databind before creating trend curve........
Me.Chart4.DataBind()
' trend ----------------------
Me.Chart4.Series.Add("TrendCurve")
Me.Chart4.Series("TrendCurve").ChartType = DataVisualization.Charting.SeriesChartType.Spline
Me.Chart4.Series("TrendCurve").BorderWidth = 3
Me.Chart4.Series("TrendCurve").BorderDashStyle = DataVisualization.Charting.ChartDashStyle.Dash
Me.Chart4.Series("TrendCurve").IsVisibleInLegend = False
' ************* calculate trend line **************
Me.Chart4.DataManipulator.FinancialFormula(
       DataVisualization.Charting.FinancialFormula.Forecasting,
       "Exponential,1,false,false", 
       Me.Chart4.Series("Performance"), 
       Me.Chart4.Series("TrendCurve"))
</code></pre>

<p>Also, the trend "curve" appears as line, although I selected "exponential" and I'd expect it to be slightly curved...</p>

<p><em>EDIT:</em> I tried to fill the first dataset point by point instead by a dataset (because examples show it this way), but as I expected, it had no effect.</p>