Show Additional information in stock charts

[ansh-FF]

Hi Team,

I’m working with a stock chart and need to display additional contextual information directly on the chart—typically over or near individual candles.

Use case:

• Display icons on the chart (for example, above a candle).
• On hover, show detailed information (news, fundamental data, events, etc.).
• During major/global events, there could be many such data points on a single chart.

I’ve seen examples where createAxisRange with bullet is used (e.g., for dividend markers), and I’m considering a similar approach. I’d like your guidance on the following:

• Is using axisRange + bullet the recommended and lightweight approach for this scenario?
• How does this scale performance-wise if I add hundreds of such markers?
• Will this have a noticeable impact on zooming, panning, or scrolling performance?
• Are there alternative components or best practices for handling a large number of event markers efficiently?

Any recommendations or performance considerations would be really helpful.

Thanks!

[martynasma]

Using axis range bullets is a good way to do it because it's asymmetric from actual data. You don't need to think how to bind to a specific data point. The downside is that it will be attached to axis, not the actual candle/datapoint.

Another alternatives to consider:

• Axis bullets
• Selectively adding bullets to series data items

In terms of performance, a couple hundred of bullets should not affect the performance, regardless of how you do it. Though, as with anything else, actual results might depend on the implementation. Something to test and find out.

[ansh-FF]

@martynasma I want to display this as an indicator (so it appears in the indicator list). I extended am5stock.Indicator, added a line series to it, attached bullets to the series, and then hid the series itself.

This approach works to some extent, but the problem is that when I zoom in on the candles, some of the arrows/bullets disappear. When I zoom out, they appear again.

I think the issue might be that I have multiple data points with the same date (for example, 12 items all with date: 1770249600000). Since they share the same X value, this might be causing rendering issues with the bullets. The chart may only display one bullet per X value or behave unexpectedly when zooming.

Do you have any suggestions? I just want it to behave like an indicator, but only display some icons over the candlesticks. It feels like I might be overcomplicating the solution.

Also attaching the codepen to try it out :
https://codepen.io/Ansh-m-the-reactor/pen/WbvoNeK

Steps to reproduce :

1. Apply My indicator
2. Zoom-in to the 6th feb candle such that only that candle is there in the view.

You will see the arrows disappear.

[ansh-FF]

Hi @zeroin , @martynasma Can you please help regarding this issue?

Sorry for tagging.

[martynasma]

I'm sorry, but we do not have the capacity to review your custom indicator code 😞

[ansh-FF]

No no @martynasma , I am not asking to review it, I am just asking is it a know/unknown bug ?
That If I push multiple data points with the same date, with bullets attached then it disappears ?

As on debugging we found it this piece of code is doing the job (core/render/Series.ts file)

[martynasma]

It's not a known bug. The hiding of bullets when zooming can come from different sources:

1. If you have minBulletDistance set on series.
2. When you zoom in enough for data item grouping to be disabled and the bullet/dataitem timestamps do not match.

[ansh-FF]

Then its a reproducible bug. You can try in your system too, as attached in this message (#2015 (comment)

1. I didn't set any property like this minBulletDistance .
2. I was just zooming till 1-2 candle in the view. So I think its pretty normal

@martynasma

[ansh-FF]

@martynasma Are we considering it as a bug?

[martynasma]

We're not considering it as a bug.

It's a tricky situation. We don't have the capacity to debug custom indicators, so unless you can provide a distilled demo with clearly demonstrable bug with regular series/data, we'll need to sit this one out 😣

[ansh-FF]

Aahh I thought providing the working codepen link and the exact reproducible way was enough !
https://codepen.io/Ansh-m-the-reactor/pen/WbvoNeK

And even in my custom indicator I am not doing anything special just setting a constant data on a line series.

@martynasma 😢

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