Finance analytics demo • public-data market surface

U.S. Market Heatmap

Large-cap U.S. stocks grouped by sector, sized by market cap, and colored by daily move.

This page is a recruiter-facing product demo, not an investing terminal. The point is to show how raw public market data can be normalized, cached, and turned into a cleaner decision surface than a flat quote table. It uses server-side refresh logic, safe disk caching, and a fallback snapshot so the page stays useful even when upstream data is delayed or unavailable.

Built with: Apache ECharts treemap
Data posture: public inputs + server-side normalization
Refresh cadence: hourly during regular NYSE hours
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Live surface

Heatmap preview

The chart sits directly below the hero and can expand into a larger modal for closer inspection. Click any tile or use the expand button.

Market heatmap

Loading latest available snapshot…

Checking market status…

Building the market surface…

Loading the latest normalized snapshot and preparing the treemap.

Daily move legend
-6% or worse -3% 0% +3% +6% or better

Tiles are sized by market cap and colored by daily percent move. Neutral or missing values stay closer to slate. Click the preview or the expand button for the larger modal view.

Live refresh runs hourly during regular NYSE hours only. When the market is closed, the page keeps the last successful market-hours snapshot and labels it clearly.

Why the refresh note matters
  • This page is designed to be honest about cadence rather than implying minute-by-minute coverage it does not provide.
  • During regular NYSE hours, the snapshot refreshes hourly.
  • When the market is closed, the page keeps the last successful market-hours snapshot instead of pretending the data is freshly updated.