Relative Strength Index

Relative Strength Index (RSI) indicator for FinancialChart is a momentum oscillator, which measures velocity and magnitude of price movements. It compares the upward movements in closing price of an asset to the downward movements over a trading period, and intends to determine strength or weakness of a stock. It fluctuates between 0 and 100. The stocks with strong positive changes have a higher RSI than the stocks with strong negative changes.

It finds application in comparing the magnitude of recent gains to recent losses, to determine the overbought and oversold conditions of an asset. Stocks are considered overbought when RSI is above 70, and oversold when below 30.

Notice that the given code snippet uses a class DataService.cs. To see the code for the class, refer to Average True Range.

Visual Basic
C#

Visual Basic

Partial Public Class Indicators
    Inherits Page
    Private dataService As DataService = dataService.GetService()

    Private rsi As New RSI() With {
        .SeriesName = "RSI"
    }
    Public Sub New()
        InitializeComponent()
    End Sub

    Public ReadOnly Property Data() As List(Of Quote)
        Get
            Return dataService.GetSymbolData("box")
        End Get
    End Property

    Public ReadOnly Property IndicatorType() As List(Of String)
        Get
            Return New List(Of String)() From {
                "Relative Strength Index",
            }
        End Get
    End Property

    Sub OnIndicatorTypeSelectionChanged(sender As Object, e As SelectionChangedEventArgs)
        Dim ser As FinancialSeries = Nothing

        If cbIndicatorType.SelectedIndex = 1 Then
            ser = rsi
        End If

        If ser IsNot Nothing AndAlso Not indicatorChart.Series.Contains(ser) Then
            indicatorChart.BeginUpdate()
            indicatorChart.Series.Clear()
            indicatorChart.Series.Add(ser)
            indicatorChart.EndUpdate()
        End If
    End Sub

    Sub OnCbPeriodValueChanged(sender As Object, e As PropertyChangedEventArgs(Of Double))
        rsi.Period = 14
    End Sub

    Sub OnFinancialChartRendered(sender As Object, e As RenderEventArgs)
        If indicatorChart IsNot Nothing Then
            indicatorChart.AxisX.Min = (CType(financialChart.AxisX, IAxis)).GetMin()
            indicatorChart.AxisX.Max = (CType(financialChart.AxisX, IAxis)).GetMax()
        End If
    End Sub
End Class

public partial class Indicators : Page
{
    DataService dataService = DataService.GetService();
    RSI rsi = new RSI() { SeriesName = "RSI" };

    public Indicators()
    {
        InitializeComponent();
    }

    public List<Quote> Data
    {
        get
        {
            return dataService.GetSymbolData("box");
        }
    }

    public List<string> IndicatorType
    {
        get
        {
            return new List<string>()
            {
                "Relative Strength Index",
            };
        }
    }

    void OnIndicatorTypeSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        FinancialSeries ser = null;
        if (cbIndicatorType.SelectedIndex == 0)
            ser = rsi;

        if (ser != null && !indicatorChart.Series.Contains(ser))
        {
            indicatorChart.BeginUpdate();
            indicatorChart.Series.Clear();
            indicatorChart.Series.Add(ser);
            indicatorChart.EndUpdate();
        }
    }

    void OnCbPeriodValueChanged(object sender, PropertyChangedEventArgs<double> e)
    {
        rsi.Period = 14;
    }

    void OnFinancialChartRendered(object sender, RenderEventArgs e)
    {
        if (indicatorChart != null)
        {
            indicatorChart.AxisX.Min = ((IAxis)financialChart.AxisX).GetMin();
            indicatorChart.AxisX.Max = ((IAxis)financialChart.AxisX).GetMax();
        }
    }
}