Live S&P 500 Stock Market Heatmap

Real-time stock market heatmap showing the top 50 S&P 500 stocks by market cap. Sized by market capitalization and colored by daily price change — green for gains, red for losses. Grouped by sector including Technology, Healthcare, Finance, Energy, and Consumer. Auto-refreshes with live data from Finnhub. Free alternative to Finviz heatmap with a cleaner mobile experience.