trail1.vl

{
    "height": 400,
    "mark": "trail",
    "data": {
        "url": "https://vega.github.io/vega-lite/data/stocks.csv"
    },
    "width": 400,
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "encoding": {
        "color": {
            "field": "symbol",
            "type": "nominal"
        },
        "size": {
            "field": "price",
            "type": "quantitative"
        },
        "x": {
            "field": "date",
            "type": "temporal",
            "axis": {
                "format": "%Y"
            }
        },
        "y": {
            "field": "price",
            "type": "quantitative"
        }
    }
}