This area chart shows the daily closing price of the S&P 500 index over time, with a filled region beneath the line to emphasize the trend in price levels. The visualization is implemented using Vega-Lite v5, with the `area` mark and a temporal x-axis encoding for the date and a quantitative y-axis for price. Data is loaded remotely from a CSV file hosted on GitHub, and the chart is rendered in an HTML page via the Vega library, which parses the specification and draws the result.