marker in core -Plot

 // OHLC plot
    CPTMutableLineStyle *whiteLineStyle = [CPTMutableLineStyle lineStyle];
    whiteLineStyle.lineColor = [CPTColor whiteColor];
    whiteLineStyle.lineWidth = 1.0f;
    CPTTradingRangePlot *ohlcPlot = [[[CPTTradingRangePlot alloc] initWithFrame:graph.bounds] autorelease];
    ohlcPlot.identifier = @"OHLC";
    ohlcPlot.lineStyle = whiteLineStyle;
    CPTMutableTextStyle *whiteTextStyle = [CPTMutableTextStyle textStyle];
    whiteTextStyle.color = [CPTColor whiteColor];
    whiteTextStyle.fontSize = 48.0;
    ohlcPlot.labelTextStyle = whiteTextStyle;
    ohlcPlot.labelOffset = 5.0;
    ohlcPlot.stickLength = 2.0f;
    ohlcPlot.dataSource = self;
    ohlcPlot.plotStyle = CPTTradingRangePlotStyleOHLC;
    [graph addPlot:ohlcPlot];