S&P 500 Heatmap FAQ

What is the S&P 500 heatmap?

It is a treemap of S&P 500 constituents. Each tile is one name, sized by market capitalization (or strategy weight) and colored by its percentage price change — green for gains, red for losses. Tiles are grouped by sector so you can read breadth at a glance.

Which time periods can I color by?

Switch among 1D (today vs prior close), 1W, 1M, YTD, and 1Y. Longer windows use LOPJLB’s local daily price history; the page URL includes ?period= so shares deep-link to the same window.

How often does the heatmap update?

Live quotes refresh through the LOPJLB market-data poller and the page repolls about every minute during market hours. Multi-day coloring uses cached daily closes plus the latest quote.

What do the tile sizes mean?

Tile area is proportional to market capitalization, so the largest names dominate the map. When a market cap is unavailable we approximate size from index or equal weight.

Where does the constituent list come from?

Members come from the SPY ETF holdings, which track the S&P 500.

Is the market heatmap investment advice?

No. The heatmap is market context for research only — not a recommendation to buy or sell any security.

Related: stock screener, market hours, and Treasury rates.