Treemap for Stock Sector Weights — S&P 500 & Equity Index Heatmap
A stock sector treemap partitions index or fund capitalization into area-proportional sector tiles ($Area_i \propto MarketCap_i / \sum MarketCap$) to reveal sector concentration risk.
Tip: Paste Excel or Google Sheets rows (Ctrl+V / ⌘V) directly into any cell.
| # | Label | ||
|---|---|---|---|
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 | |||
| 8 | |||
| 9 |
Sector weight: w_i = Cap_i / sum(Cap). Herfindahl-Hirschman Concentration Index: HHI = sum((w_i)^2).
Chart Design & Use-Case Tips
- 01Sector weight: w_i = Cap_i / sum(Cap). Herfindahl-Hirschman Concentration Index: HHI = sum((w_i)^2).
- 02Enter either GICS sector percentage weights (summing to 100%) or individual stock position market values ($K).
- 03Immediately reveals whether a portfolio is heavily concentrated in Information Technology and Communication Services (>40% combined).
- 04Toggle data labels ON to read exact sector weights inside every rectangular block.
Frequently Asked Questions
Why do financial terminals (Bloomberg, Finviz) use treemaps for market sectors?+
Because market capitalization spans an order of magnitude from Tech (~31%) down to Materials/Energy (~3%), and rectangular tiling packs all 11 GICS sectors into a dense, readable heatmap.
Can I enter individual stock tickers (NVDA, AAPL, MSFT, AMZN) instead of sectors?+
Yes! Replace the row labels with your portfolio tickers and enter dollar position sizes in Series A.
How do I compare portfolio weights against the S&P 500 benchmark?+
Use the Grouped Bar Chart Maker with Series A = Portfolio Weight and Series B = S&P 500 Weight to inspect active overweight/underweight tilts.