Thematic vs. Sector ETFs by the Numbers: Funds, Size and Flows

By Adam Patti, Chief Executive Officer, VistaShares | Published November 13, 2026

Sector ETFs divide the stock market by industry; thematic ETFs cut across industries to follow an idea such as AI, defense or clean energy. The numbers show how differently the two categories are built: hundreds of thematic funds spread across dozens of themes, against a smaller set of sector funds where a few very large funds hold most of the money. This page compares them with dated figures.

Figure	Thematic ETFs	Sector ETFs
How ETFIQ groups them (Nov 12, 2026)	55 themes	12 sector segments
Funds tracked by ETFIQ (Nov 12, 2026)	428	Technology 26; health care 25; energy 32; financials 31
Largest single fund, net assets	$65.1 billion (Nov 11 to 12, 2026)	Technology $145.1 billion (Oct 31, 2026); financials $54.2 billion, health care $50.5 billion, energy $41.6 billion (Nov 11, 2026)
Typical fund’s weight in S&P 500 stocks	31.8% (Nov 12, 2026)	Not published as a category figure
Fee reference point	Median fee 0.56%, 227 thematic ETFs (second quarter of 2026)	Asset-weighted average 0.14% for all index equity ETFs, sector and broad (2025, ICI)
Net flows, month to Nov 11, 2026	$5.5 billion in, 213 funds counted	All stock ETFs, sector funds included: $61.0 billion in, 795 funds counted
Net flows, week to Nov 11, 2026	$294 million in, 205 funds counted	Technology $882 million in; energy $862 million out
U.S. category size, Morningstar (Sep 30, 2025)	332 thematic funds, $180 billion	Not part of the cited source

Sources: thematic counts, largest fund and S&P 500 weight, ETFIQ thematic ETFs and ETFIQ ETF statistics, data as of Nov 12, 2026; median fee, ETFIQ Quarterly, 2026-Q2; sector counts, ETFIQ stock ETFs, and largest funds, technology, financials, health care and energy pages, as of Nov 12, 2026; flows, ETFIQ fund flows, as of Nov 11, 2026; ICI and Morningstar, notes 1 and 2.

How are the two categories defined?

A sector ETF holds companies from one industry group, such as technology, health care, energy or financials, usually following a standard industry classification. Because the classification covers the whole market, every company belongs to exactly one sector. A thematic ETF picks companies tied to a trend or idea, wherever they sit in the industry classification. An AI fund can hold chipmakers, software firms and utilities in the same portfolio.

ETFIQ grouped U.S. thematic ETFs into 55 themes as of November 12, 2026, while it placed sector funds into 12 sector segments. Our article on how to evaluate a thematic ETF explains what to check inside a theme.

How many funds are there?

ETFIQ tracked 428 thematic ETFs on November 12, 2026. Sector counts were much smaller per group: 26 technology funds, 25 health care, 32 energy and 31 financials, among others. The thematic count is spread across many narrow ideas, from cybersecurity to space to rare earths, so many themes have only a handful of funds.

Morningstar counted 332 U.S. thematic funds holding $180 billion at the end of September 2025, up 50% over three years.² Morningstar’s definition and date differ from ETFIQ’s, which is why the two counts are not the same.

How large are the biggest funds?

The largest thematic ETF held $65.1 billion as of November 11 to 12, 2026. The largest technology sector ETF held $145.1 billion as of October 31, 2026, more than twice as much. The largest financials, health care and energy sector funds each held between $41.6 billion and $54.2 billion on November 11, 2026.

Thematic money is spread across many more funds, so the typical thematic fund is far smaller than the leading sector funds. The theme with the largest fund, semiconductors, is itself close to an industry group.

How do fees compare?

ETFIQ found a median fee of 0.56% across 227 thematic ETFs that traded through the second quarter of 2026, and thematic fees overall ran from 0.00% to 1.32% as of November 2026. ICI reported an asset-weighted average expense ratio of 0.14% for index equity ETFs in 2025, a group that includes sector index funds along with broad market funds.¹

The two figures measure different things, a median for one category and an asset-weighted average for a much broader one, so they are reference points rather than a direct comparison. Even so, the gap is wide enough that fees deserve a close look when choosing a thematic fund.

Do thematic ETFs overlap with the broad market?

More than many investors expect. The typical thematic ETF carried 31.8% of its weight in S&P 500 stocks as of November 12, 2026. A sector fund made of large U.S. companies sits largely inside the index by design. Our article on ETF portfolio overlap explains how to check what a fund adds to a core holding.

Where has money been flowing?

In the month to November 11, 2026, thematic ETFs with daily data took in a net $5.5 billion across 213 funds, while stock ETFs as a whole, sector funds included, took in $61.0 billion across 795 funds. Sector flows can split sharply in a single week: in the week to November 11, technology funds took in $882 million while energy funds had a net outflow of $862 million.

Flow figures are estimated from daily changes in shares outstanding and cover only funds with daily share data, so they are a sample of each category.

How do investors use each?

Sector funds: often used to adjust industry weights around a core holding, or to express a view on one part of the economy.

Thematic funds: often used as a smaller satellite position for a long-term idea that cuts across industries. Our article on core and satellite investing explains the approach.

More thematic articles are in the Thematic ETF Guide.

Frequently asked questions

Are there more thematic ETFs or sector ETFs?

By ETFIQ’s count on November 12, 2026, there were 428 thematic ETFs. Sector groups held far fewer funds each, such as 26 technology and 25 health care funds.

Are thematic ETFs more expensive than sector ETFs?

On the available figures, thematic funds tend to charge more. The median thematic ETF fee was 0.56% in the second quarter of 2026, while ICI put the asset-weighted average for index equity ETFs at 0.14% in 2025. The two figures are measured differently, and individual funds vary.

Can a theme and a sector overlap?

Yes. A semiconductor theme sits mostly inside the technology sector, for example. Other themes, such as AI or clean energy, span several sectors.

How many themes are there?

ETFIQ grouped thematic ETFs into 55 themes as of November 12, 2026. Other data providers use their own lists and may count differently.

Which is larger, the biggest sector ETF or the biggest thematic ETF?

The largest technology sector ETF held $145.1 billion on October 31, 2026, more than twice the $65.1 billion in the largest thematic ETF as of November 11 to 12, 2026.

Do flows show which category is better?

No. Flows show where investors moved money over a past window. They say nothing about which category suits a given portfolio.

Adam Patti, Chief Executive Officer of VistaShares, is also the founder of ETFIQ. ETFIQ does not accept payment from ETF issuers, and its figures are calculated from public filings and market data.

Cite this page: Adam Patti, "Thematic vs. Sector ETFs by the Numbers: Funds, Size and Flows," VistaShares, updated November 13, 2026, https://www.vistashares.com/thematic-vs-sector-etfs-by-the-numbers/. Plain-text version.

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