A map of a selected market
A stock heatmap groups many companies into coloured tiles. First check which market or index is selected. Market Muse’s stock heatmap offers the S&P 500 and Nasdaq 100. These are different groups of companies, so they will not give identical pictures.
Size and colour answer different questions
In our stock heatmap, tile size represents company market capitalisation. Colour represents percentage price change over the selected period. A large green tile is a large company whose price has risen; it is not necessarily the day’s biggest percentage winner. Check the provider’s legend because other maps can use different settings.
A simple example
Suppose a large company rises 1% while a much smaller company rises 8%. The large company can occupy more space, even though its percentage gain is lower. These fictional figures show why the biggest tile and the biggest mover are different ideas.
Look for clusters, then investigate
If many tiles in one sector share a colour, companies in that group may be responding to similar conditions. Open individual symbols and look for earnings reports or industry news. Colour alone cannot identify the cause. A few very large companies can also dominate the visual impression.
Check the clock and the coverage
A stock session change is not the same as a rolling crypto 24-hour change. Delayed feeds, closed exchanges and different currencies can affect comparisons. The map only shows its selected universe; it is not a complete picture of every investment.
Use the map as a starting point
Pick a tile, check its symbol and measurement period, then read the company’s announcement and chart. A red tile is not automatically a bargain, and a green tile is not a recommendation. Use the research guide before drawing conclusions.
Sources and further reading
Provider settings and financial products can change. Check original sources before acting. These guides explain concepts and do not recommend individual investments.