MarketCapLens ranks 11 industry sectors by combined market cap — 2,493 U.S.-listed companies with a market cap of at least $1B. As of October 19, 2026, Technology is the largest at $33.75T (33.94% of tracked market cap). Combined size is not a sector return — What is a sector? explains how a handful of companies can dominate a total.
Compare sectors
U.S. stock market sectors compared by combined market cap, company count, median company size, largest company, top-three concentration, and share of tracked market cap. Sortable by column.
Sectors are broad industry groups that classify public companies by what they do — for example Technology, Financial Services, or Health Care. MarketCapLens currently tracks 11 sectors covering 2,493 U.S.-listed companies with a market cap of at least $1B.
How are companies classified?
Each ranking row has one sector string from Financial Modeling Prep (GICS-style groups such as Technology or Financial Services). MarketCapLens does not license GICS or remap those labels. A company belongs to one sector. Sectors with fewer than 3 companies above the $1B floor are omitted. Untagged names still sit in the universe total, so sector shares of tracked market cap need not sum to 100%.
What is a sector ranking?
Each sector page lists U.S.-listed companies in that industry group with a market cap of at least $1B, ranked by market capitalization in USD. Combined sector market cap and each company's weight within the sector are shown alongside price and daily change.
How is sector market cap calculated?
Click a column to sort. Combined cap is a size snapshot of companies above the $1B floor, not a sector return. Median size is the typical company in that sector. Top 3 is the share of the three largest names. Share of tracked is that sector versus every company on MarketCapLens, including untagged names. As of October 19, 2026.
Sector market cap is the sum of each constituent company's market cap. A company's weight is its market cap divided by that sector total. Share of tracked market cap is the sector's combined cap as a fraction of every company tracked on MarketCapLens, including untagged names and thin sectors that do not get their own page.
Which companies are included?
MarketCapLens includes common equity listed on NASDAQ, NYSE, or AMEX that clears the $1B market-cap floor and is actively trading. ETFs, funds, preferred shares, equity units, and warrants are excluded. Dual share classes of the same company are counted once.
How is this different from Featured AI and Memory?
Sectors partition the tracked universe by industry label: each company is in one sector. Featured lists (Magnificent 7, AI stocks, and memory stocks) are smaller editorial comparisons and can overlap — the same company can appear on more than one Featured list. Open Featured to compare those groups.
Do you show sector returns?
No. Combined market cap is a size snapshot. It can change because companies got larger or smaller, names crossed the floor, or the mix of constituents changed. That is not a cap-weighted or equal-weighted sector return, and we do not persist constituent dates.
Which sector has the largest market cap?
As of October 19, 2026, Technology is the largest sector on MarketCapLens at $33.75T — 33.94% of tracked market cap, led by NVIDIA Corporation (NVDA) at $5.23T.
Which sector has the most companies?
As of October 19, 2026, Financial Services has the most constituents (404 companies above the $1B floor), even though Technology leads by combined market cap.
How often are sector rankings updated?
Prices and market caps refresh throughout the trading day, and sector pages rebuild from the latest snapshot. The "as of" date on this page (currently October 19, 2026) shows when the ranking was last published.