[XtraChartsLocalizableCategory(XtraChartsCategory.Layout)]
public int LineThickness { get; set; }

<XtraChartsLocalizableCategory(XtraChartsCategory.Layout)>
Public Property LineThickness As Integer

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
using DevExpress.XtraCharts;
//...
    private void Form1_Load(object sender, EventArgs e) {
        // Create a new chart.
        ChartControl stockChart = new ChartControl();

        // Create a stock series.
        Series series1 = new Series("Series 1", ViewType.Stock);

        // Bind the series to data.
        series1.DataSource = GetDataPoints();
        series1.SetFinancialDataMembers("Argument", "Low", "High", "Open", "Close");

        // Specify that date-time arguments are expected.
        series1.ArgumentScaleType = ScaleType.DateTime;

        // Add the series to the chart.
        stockChart.Series.Add(series1);

        // Customize the series view settings.
        StockSeriesView view = (StockSeriesView)series1.View;

        view.LineThickness = 2;
        view.LevelLineLength = 0.25;

        // Specify the series reduction options.
        view.ReductionOptions.ColorMode = ReductionColorMode.OpenToCloseValue;
        view.ReductionOptions.Level = StockLevel.Close;
        view.ReductionOptions.Visible = true;

        // Set point colors.
        view.Color = Color.Green;
        view.ReductionOptions.Color = Color.Red;

        // Access the chart's diagram.
        XYDiagram diagram = (XYDiagram)stockChart.Diagram;

        // Exclude empty ranges from the X-axis range
        // to avoid gaps in the chart's data.
        diagram.AxisX.DateTimeScaleOptions.SkipRangesWithoutPoints = true;

        // Hide the range without points at the beginning of the y-axis.
        diagram.AxisY.WholeRange.AlwaysShowZeroLevel = false;

        // Hide the legend.
        stockChart.Legend.Visibility = DevExpress.Utils.DefaultBoolean.False;

        // Add a title to the chart.
        stockChart.Titles.Add(new ChartTitle());
        stockChart.Titles[0].Text = "Stock Chart";

        // Add the chart to the form.
        stockChart.Dock = DockStyle.Fill;
        this.Controls.Add(stockChart);
    }

    List<DataPoint> GetDataPoints() {
        List<DataPoint> dataPoints = new List<DataPoint> {
            new DataPoint(DateTime.Now.AddDays(-9), 24.00, 25.00, 25.00, 24.875),
            new DataPoint(DateTime.Now.AddDays(-8), 23.625, 25.125, 24.00, 24.875),
            new DataPoint(DateTime.Now.AddDays(-7), 26.25, 28.25, 26.75, 27.00),
            new DataPoint(DateTime.Now.AddDays(-6), 26.50, 27.875, 26.875, 27.25),

            new DataPoint(DateTime.Now.AddDays(-4), 25.75, 26.875, 26.75, 26.00),
            new DataPoint(DateTime.Now.AddDays(-3), 25.75, 26.75, 26.125, 26.25),
            new DataPoint(DateTime.Now.AddDays(-2), 25.75, 26.375, 26.375, 25.875),
            new DataPoint(DateTime.Now.AddDays(-1), 24.875, 26.125, 26.00, 25.375),
            new DataPoint(DateTime.Now.AddDays(0), 25.125, 26.00, 25.625, 25.75),
            };
        return dataPoints;
    }
}
public class DataPoint {
    public DateTime Argument { get; set; }
    public double Low { get; set; }
    public double High { get; set; }
    public double Open { get; set; }
    public double Close { get; set; }
    public DataPoint(DateTime arg, double low, double high, double open, double close) {
        this.Argument = arg;
        this.Low = low;
        this.High = high;
        this.Open = open;
        this.Close = close;
    }
}

using System
using System.Collections.Generic
using System.Drawing
using System.Windows.Forms
using DevExpress.XtraCharts
'...
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
        ' Create a new chart.
        Dim stockChart As ChartControl = New ChartControl()

        ' Create a stock series.
        Dim series1 As Series = New Series("Series 1", ViewType.Stock)

        ' Bind the series to data.
        series1.DataSource = GetDataPoints()
        series1.SetFinancialDataMembers("Argument", "Low", "High", "Open", "Close")

        ' Specify that date-time arguments are expected.
        series1.ArgumentScaleType = ScaleType.DateTime

        ' Add the series to the chart.
        stockChart.Series.Add(series1)

        ' Customize the series view settings.
        Dim view As StockSeriesView = CType(series1.View, StockSeriesView)
        view.LineThickness = 2
        view.LevelLineLength = 0.25

        ' Specify the series reduction options.
        view.ReductionOptions.ColorMode = ReductionColorMode.OpenToCloseValue
        view.ReductionOptions.Level = StockLevel.Close
        view.ReductionOptions.Visible = True

        ' Set point colors.
        view.Color = Color.Green
        view.ReductionOptions.Color = Color.Red

        ' Access the chart's diagram.
        Dim diagram As XYDiagram = CType(stockChart.Diagram, XYDiagram)

        ' Exclude empty ranges from the X-axis range
        ' to avoid gaps in the chart's data.
        diagram.AxisX.DateTimeScaleOptions.SkipRangesWithoutPoints = True

        ' Hide the range without points at the beginning of the y-axis.
        diagram.AxisY.WholeRange.AlwaysShowZeroLevel = False

        ' Hide the legend.
        stockChart.Legend.Visibility = DevExpress.Utils.DefaultBoolean.[False]

        ' Add a title to the chart.
        stockChart.Titles.Add(New ChartTitle())
        stockChart.Titles(0).Text = "Stock Chart"

        ' Add the chart to the form.
        stockChart.Dock = DockStyle.Fill
        Me.Controls.Add(stockChart)
    End Sub

    Private Function GetDataPoints() As List(Of DataPoint)
        Dim dataPoints As List(Of DataPoint) = New List(Of DataPoint) From {
            New DataPoint(Date.Now.AddDays(-9), 24.00, 25.00, 25.00, 24.875),
            New DataPoint(Date.Now.AddDays(-8), 23.625, 25.125, 24.00, 24.875),
            New DataPoint(Date.Now.AddDays(-7), 26.25, 28.25, 26.75, 27.00),
            New DataPoint(Date.Now.AddDays(-6), 26.50, 27.875, 26.875, 27.25),

            New DataPoint(Date.Now.AddDays(-4), 25.75, 26.875, 26.75, 26.00),
            New DataPoint(Date.Now.AddDays(-3), 25.75, 26.75, 26.125, 26.25),
            New DataPoint(Date.Now.AddDays(-2), 25.75, 26.375, 26.375, 25.875),
            New DataPoint(Date.Now.AddDays(-1), 24.875, 26.125, 26.00, 25.375),
            New DataPoint(Date.Now.AddDays(0), 25.125, 26.00, 25.625, 25.75)
        }
        Return dataPoints
    End Function

Dim view As CandleStickSeriesView = CType(series1.View, CandleStickSeriesView)
view.LineThickness = 2
view.LevelLineLength = 0.25