Tooltip with Multi-Series Line Chart in Vega-Lite API

I am trying to recreate this example in Vega-Lite API in an Observable notebook. I am able to recreate the ruler with the multiple line series from another example in Observable. But I am having trouble adding tooltips, I would like to add the symbol ticker and the price of the stock of each stock. Instead it looks like this in my Observable notebook.



Thank you this is perfect!

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