Multi Series Line Chart with Labels

The plot displays labels for all stock prices of the hovered time. The example is forked/modified from @jakevdp’s block.

View this example in the online editor

Vega-Lite JSON Specification

{
  "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
  "data": {
    "url": "data/stocks.csv"
  },
  "width": 400,
  "height": 300,
  "layer": [
    {
      "encoding": {
        "x": {"field": "date", "type": "temporal"},
        "y": {"field": "price", "type": "quantitative"},
        "color": {"field": "symbol", "type": "nominal"}
      },
      "layer": [
        {"mark": "line"},
        {
          "selection": {
            "label": {
              "type": "single",
              "nearest": true,
              "on": "mouseover",
              "encodings": ["x"],
              "empty": "none"
            }
          },
          "mark": "point",
          "encoding": {
            "opacity": {
              "condition": {"selection": "label", "value": 1},
              "value": 0
            }
          }
        }
      ]
    },
    {
      "transform": [{"filter": {"selection": "label"}}],
      "layer": [
        {
          "mark": {"type": "rule", "color": "gray"},
          "encoding": {
            "x": {"type": "temporal", "field": "date", "aggregate": "min"}
          }
        },
        {
          "encoding": {
            "text": {"type": "quantitative", "field": "price"},
            "x": {"type": "temporal", "field": "date"},
            "y": {"type": "quantitative", "field": "price"}
          },
          "layer": [
            {
              "mark": {
                "type": "text",
                "stroke": "white",
                "strokeWidth": 2,
                "align": "left",
                "dx": 5,
                "dy": -5
              }
            },
            {
              "mark": {"type": "text", "align": "left", "dx": 5, "dy": -5},
              "encoding": {
                "color": {"type": "nominal", "field": "symbol"}
              }
            }
          ]
        }
      ]
    }
  ]
}