Plot.plot({
y: {grid: true},
marks: [
() => htl.svg`<defs>
<linearGradient id="gradient" gradientTransform="rotate(90)">
<stop offset="20%" stop-color="steelblue" stop-opacity="0.5" />
<stop offset="100%" stop-color="brown" stop-opacity="0" />
</linearGradient>
</defs>`,
Plot.areaY(aapl, {x: "Date", y: "Close", fill: "url(#gradient)"}),
Plot.lineY(aapl, {x: "Date", y: "Close", stroke: "steelblue"}),
Plot.ruleY([0])
]
})