Stock Market Heatmap
A live heat map of the 160 largest S&P 500 companies: tile size is live market cap, color is today’s move. Green up, red down. Click any tile for its full chart. Below the map, every sector’s total return by window.
About this tool
This stock market heat map draws the 160 largest S&P 500 companies as tiles: tile size is live market capitalization, color is today's price move. One glance shows which sectors are carrying the market and which are dragging it, and clicking any tile opens a full price chart.
Because area tracks market cap, the heatmap doubles as a concentration snapshot. A handful of mega-cap technology names now make up a historically large share of the US market, which is why index investors are more exposed to a few companies than the phrase "diversified index fund" suggests.
What is a stock market heat map?
A single picture of a whole market. Each company is a rectangle, sized by how large the company is and shaded by how its share price has moved, so you can read the day, or the sector driving it, without scanning a list of hundreds of tickers.
What do the heat map colors mean?
Green tiles are stocks trading up today and red tiles are down, with deeper shades marking bigger moves. Grey means little change.
Why are some tiles so much bigger than others?
Tile area is proportional to market capitalization, the total value of all the company's shares. The biggest US companies are worth trillions of dollars, so their tiles dwarf everything else.
How often does the heatmap update?
Prices refresh continuously while US markets are open.