Hi there,
Welcome to our forum and thank you for contacting us with this question.
I'll explain to you how you can achieve the same formatting on a candlestick chart as on the line chart.
First of all, you need to remember that this is a shared tooltip, so the properties are structured a bit differently than in a standard one.
You can create your tooltip in the tooltip.formatter method.
Since it's a shared tooltip, the return is an array, where the first item is a xAxis tooltip, and the second one is the tooltip from the chart area.
Also please note, that the line chart and candlestick chart show the same data in a slightly different form (hence the difference in tooltips).
The line chart shows you the close price of a certain asset, where a candlestick represents an open, high, low, close price in a given timeframe (i.e 5 minute bar).
I have attached a simple demo with a formatting example, so please take a look at it and check the official API documentation.
DEMO: https://jsfiddle.net/BlackLabel/jqtvh7u6/
API Reference: https://api.highcharts.com/highstock/tooltip.formatter
https://api.highcharts.com/class-refere ... ckFunction
https://api.highcharts.com/class-refere ... dateFormat
Let me know if that is what you were looking for,
Regards!