Tools · Live Market Map
Nasdaq 100 Heatmap
All Nasdaq 100 companies as one block each: sized by market cap, grouped by GICS sector, colored by today’s move. Hover or tap a block for the price, change and market cap behind it.
After-hours change vs today's 4:00pm ET close · Updated 4:04 PM EDT
How to Read a Market Heatmap
A market heatmap compresses an entire index into one picture. Each rectangle is a company, its area is proportional to market capitalization, and its color is the day's percentage move: green for up, red for down, with intensity capped at a 3% move. Because the blocks are grouped into sectors, the first glance tells you where the day is happening: a sea of red with one green sector is a rotation, uniform color is a macro day, and a single deep-colored mega-cap block is a stock story big enough to move the whole index.
Size matters more than color. A 1% move in the largest technology block moves the index more than a 10% move in the smallest utility, which is exactly what the areas are telling you. That is also why cap-weighted days can feel wrong: most tiles can be green while the index falls, if the few giant tiles are red.
The session toggle switches the same map between the regular session, pre-market and after-hours. Extended-session prints are thinner and moves there routinely fade or reverse at the open, so treat the pre-market map as a watchlist, not a verdict. For what is scheduled to move these stocks next, our earnings calendar pairs naturally with this page.
Nasdaq 100 Heatmap FAQ
- What do the colors on this heatmap mean?
- Each block is colored by that stock’s percentage move for the selected session: shades of green for gains, shades of red for losses, gray for unchanged or no data. Color intensity is capped at a 3% move in either direction, so anything at the deepest green or red has moved at least 3%. Every block also shows the signed percentage when it is large enough, and the popup always carries the exact figure.
- What decides the size of each block?
- Block area is proportional to the company’s market capitalization within the Nasdaq 100, so the biggest companies take the most space, and blocks are grouped into GICS sectors sized the same way. Membership and market caps were last refreshed on 2026-08-04.
- How often do the prices update?
- Quotes refresh roughly every minute while you keep the page open during market hours, and the page itself is re-rendered with fresh prices about once a minute, so the colors you land on are already current. When the market is closed the map shows the last completed session.
- Does this heatmap show pre-market and after-hours trading?
- Yes. Use the Regular / Pre-market / After-hours toggle above the map. In pre-market mode colors show each stock’s pre-market change versus yesterday’s close; in after-hours mode they show the move since the 4:00pm ET close. Stocks that have not traded in the extended session show gray.
- Which companies are included in the Nasdaq 100 heatmap?
- All 103 Nasdaq 100 constituents in our current snapshot, including dual-listed share classes where the index holds both (for example Alphabet’s GOOGL and GOOG). Membership is re-verified weekly. The S&P 500 heatmap is one tab over.