A line chart displays the nominal closing price of the S&P 500 index from 1980 to 1998, rising from roughly 135 to over 1200. Data points are marked with circles along the path. Using D3 v5, the visualization builds SVG axes with `scaleTime` and `scaleLinear`, renders the polyline with the `line` generator and `curveLinear`, and appends circles for each yearly observation from `data.csv`.