F&O · Sector Heatmap

Prices and % change from NSE via Yahoo Finance, refreshed about once a minute by a GitHub Actions workflow; this page re-reads sector_data.json every 30 seconds while open. Each sector row shows two different things: the coloured figure is an equal-weighted average of that sector’s F&O constituents (a breadth measure), while the bar beside it is the real NSE sectoral index and where it currently sits in its own day range. They will not agree — the index is float-weighted and holds names beyond this list. 12 of the 23 groups have a sectoral index whose composition genuinely matches. The other 11 (Capital Goods, CDMO, Construction, Consumer Services, Financial Services, NBFCs, New Age Stocks, Power, Services, Telecommunication, Textiles) have none, so rather than substitute a loosely-related index they get a dashed bar built from their own constituents: each stock’s day low and high as a % move from its own previous close, averaged equal-weight. That is an envelope of the individual day ranges — it treats every stock’s low as simultaneous, which no real index does — so read it as “how far the average name in this sector travelled today”, not as an index level. Tile colours use the per-stock scale in the legend; the sector figure uses a finer scale suited to averages. Tap any tile for that stock on NSE.

Not every name here trades in F&O. Defence, New Age Stocks, CDMO and Textiles were deliberately broadened past the F&O universe. Those 15 names carry a dashed outline on their tile — same colour scale, same label, just a marker that there are no futures or options on them. Each was checked against NSE’s derivatives list via the broker instrument API and returns zero contracts. Sector groupings are a hand-maintained view, not NSE’s official classification: Financial Services here means insurance, AMCs and exchanges, with banks and lending NBFCs split into their own groups.