series.legendItem.highlight.markers.borderRadiusNumber

The border radius in pixels when type is set to "roundedRect".

Example

<div id="stock-chart"></div>
<script>
$("#stock-chart").kendoStockChart({
    dataSource: {
        data: [
            { date: new Date(2023, 1, 1), open: 100, high: 110, low: 90, close: 105 },
            { date: new Date(2023, 1, 2), open: 105, high: 115, low: 95, close: 110 }
        ]
    },
    categoryField: "date",
    series: [{
        type: "candlestick",
        openField: "open",
        highField: "high",
        lowField: "low",
        closeField: "close",
        legendItem: {
            highlight: {
                markers: {
                    type: "roundedRect",
                    borderRadius: 8
                }
            }
        }
    }]
});
</script>