Demo of yAxis options

HTML

<script src="https://code.highcharts.com/highcharts.js"></script>
<script src="https://code.highcharts.com/modules/stock.js"></script>
<script src="https://code.highcharts.com/modules/accessibility.js"></script>

<script src="https://cdn.jsdelivr.net/npm/@highcharts/[email protected]" type="module"></script>

<figure class="highcharts-figure">
  <div id="container"></div>
</figure>

<div class="highcharts-controls-wrapper">
  <highcharts-controls>
    <highcharts-group header="Update options">
      <highcharts-control type="color" path="yAxis.minorTickColor" value="#80808080"></highcharts-control>
      <highcharts-control type="number" path="yAxis.minorTickWidth" value="1" min="0" max="5"></highcharts-control>
      <highcharts-control type="number" path="yAxis.minorTickLength" value="10" min="0" max="20"></highcharts-control>
      <highcharts-control type="select" path="yAxis.minorTickPosition" value="inside" options="inside,outside"></highcharts-control>
    </highcharts-group>
  </highcharts-controls>
</div>

CSS

* {
    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        "Apple Color Emoji",
        "Segoe UI Emoji",
        "Segoe UI Symbol",
        sans-serif;
}

.highcharts-figure {
    max-width: 800px;
    margin: 1em auto;
}

.highcharts-controls-wrapper {
    max-width: 800px;
    margin: 1em auto;
    padding: 0 10px;
}

highcharts-controls {
    display: inline-block;
}

TypeScript

(async () => {

    const data = await fetch(
        'https://www.highcharts.com/samples/data/usdeur.json'
    ).then(response => response.json());

    Highcharts.stockChart('container', {
        title: {
            text: 'Demo of minor tick options'
        },
        yAxis: {
            minorGridLineWidth: 0,
            minorTickColor: '#80808080',
            minorTickLength: 10,
            minorTickPosition: 'inside',
            minorTicks: true,
            minorTickWidth: 1
        },
        series: [{
            data: data
        }]
    });

})();