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How much of a theme is already the index

By their latest holdings filings, the typical thematic ETF has 30% of its weight in stocks the S&P 500 already holds, and 74 of 379 funds are more than sixty percent index names.

Across 54 themes and 405 funds, the median fee is 0.60%; measured against only the part of each fund that differs from the S&P 500, the median fee for the difference is 0.60%. 136 pairs of funds hold portfolios that are more than half identical by weight; holding both is close to holding one of them twice.

Share on XDownload as PDFEvery thematic ETF, live
Beat the S&P 500 over one year, by theme
Broad innovation and megatrends
16 of 27
Artificial intelligence
16 of 24
Clean energy
3 of 16
Defense
0 of 14
Internet and e-commerce
0 of 13
Blockchain and crypto equities
0 of 13
Semiconductors
9 of 9
Gold miners
8 of 9
Nuclear and uranium
0 of 8
Digital infrastructure and data centers
7 of 8
Energy transition and decarbonisation
6 of 8
Healthcare innovation and GLP-1
5 of 8

70 of 157 thematic ETFs with a full year beat the S&P 500 over the year to Sep 28, 2026.

ETFIQ Narrative

A look at what thematic ETFs actually hold, as of 2026-09-28, shows a wide range in how much of their portfolios sit inside the S&P 500 already. Across 379 funds, the typical thematic ETF holds 30% of its weight in stocks the S&P 500 also holds, but 74 of those 379 funds carry more than sixty percent index names in their books. Active share, a measure of how different a fund's holdings are from the index, varies by theme. Semiconductors, with 11 funds, has a median 62% of weight already in the S&P 500 and a median active share of 85%. AI infrastructure and chips, with 11 funds, shows 63% already in the index. By contrast, gold miners, silver miners, and cannabis show active share at or near 100%, with in-index weight near zero for cannabis and in the single digits for the metals themes.

Fees tell a related story. Across 54 themes and 405 funds, the median fee is 0.60%. When that fee is measured only against the part of each fund that differs from the S&P 500, the median fee for the difference is also 0.60%, meaning the cost of the distinct, non-index portion of these portfolios lines up closely with the headline fee in the typical case. Some themes diverge: biotech carries a 0.50% median fee but a lower 0.30% fee for the difference, while artificial intelligence, broad innovation and megatrends, and several others show the fee for the difference running higher than the headline fee.

Overlap between individual funds is another dimension. The data identifies 136 pairs of funds whose portfolios are more than half identical by weight, meaning that holding both is close to holding one of them twice over. The listed examples include PDBA and EVMT in agriculture, with a 98% weight overlap, and several semiconductor pairs such as SOXQ and SOXX at 82% overlap, FTXL and SOXX at 77%, and SOXQ paired separately with SMH and SHOC at 74%. Gold miners also appears multiple times, with AUAU and GDX overlapping at 83% and GDX and GDMN at 77%. Space-themed funds ORBX, MARS, and WARP overlap with each other at 82%, 78%, and 75% respectively.

Returns over the one-year period varied widely by theme, from semiconductors at +98.4% and genomics and gene editing at +88.2% to streaming and live entertainment at −22.8% and gaming, esports and betting at −19.2%. The "beat the S&P 500" column shows how many funds in each theme outperformed over one year, ranging from 9 of 9 in semiconductors to 0 of 14 in defense and 0 of 13 in both internet and e-commerce and blockchain and crypto equities.

Readers can check any fund's current in-index weight, active share, fee for the difference, and its overlap with other named funds directly on the live desk.

Median weight already in the S&P 500, by theme
Energy security and critical technology
86%
Millennial and Gen Z consumers
66%
AI infrastructure and chips
63%
Semiconductors
62%
Digital infrastructure and data centers
62%
Artificial intelligence
56%
Cooling and thermal management
56%
Longevity and aging
55%
Broad innovation and megatrends
51%
Electrification and the grid
50%
Beauty and personal care
47%
Cloud and software
46%

Across 405 thematic ETFs on Sep 28, 2026, each bar is a theme’s median weight already in the S&P 500.

By theme, largest assets first

ThemeFundsMedian in the S&P 500Median active shareMedian feeMedian fee for the differenceBeat the S&P 500, one yearMedian total return, one year
Semiconductors1162%85%0.30%0.40%9 of 9+98.4%
Defense2239%98%0.50%0.50%0 of 14−0.3%
Gold miners105%100%0.50%0.50%8 of 9+21.9%
Artificial intelligence3656%80%0.70%0.80%16 of 24+31.8%
Memory and storage530%97%0.70%0.80%0 of 0·
Cybersecurity728%99%0.50%0.50%7 of 7+33.0%
Cloud and software846%92%0.40%0.40%3 of 7+11.2%
Infrastructure736%97%0.50%0.50%0 of 6+9.7%
Broad innovation and megatrends3051%86%0.50%0.60%16 of 27+22.2%
Nuclear and uranium1016%100%0.70%0.70%0 of 8−15.6%
Electrification and the grid1150%97%0.50%0.60%3 of 7+9.5%
Internet and e-commerce1331%95%0.70%0.70%0 of 13−14.3%
Silver miners42%100%0.50%0.50%4 of 4+30.2%
Reshoring and manufacturing1036%97%0.60%0.70%5 of 7+21.9%
Copper610%100%0.60%0.60%6 of 6+55.3%
Robotics and automation923%93%0.70%0.70%3 of 6+15.9%
Miners and metals612%100%0.60%0.60%3 of 6+17.0%
Quantum computing424%90%0.50%0.50%1 of 1+46.2%
Clean energy169%99%0.60%0.60%3 of 16+9.4%
Biotech831%99%0.50%0.30%6 of 6+52.3%
Water638%100%0.50%0.60%0 of 6−3.2%
Space1013%100%0.80%0.80%1 of 2+18.9%
Digital infrastructure and data centers962%88%0.50%0.60%7 of 8+33.4%
Therapeutics and medical devices523%98%0.70%0.70%3 of 5+29.1%
Blockchain and crypto equities1420%98%0.60%0.60%0 of 13−4.8%
Rare earth and critical materials78%100%0.60%0.60%3 of 4+20.9%
Genomics and gene editing424%99%0.50%0.50%3 of 3+88.2%
Lithium and battery metals68%100%0.60%0.60%3 of 6+14.8%
Agriculture630%100%0.60%0.60%2 of 6+16.0%
Cannabis50%100%0.80%0.80%2 of 5+14.3%
AI infrastructure and chips1163%86%0.70%0.80%2 of 2+44.3%
Fintech and digital payments639%98%0.70%0.70%0 of 4−17.4%
Shipping, aviation and logistics636%99%0.60%0.60%3 of 4+35.9%
Energy security and critical technology586%95%0.50%0.60%1 of 3+15.8%
Electric vehicles and batteries820%98%0.60%0.60%2 of 6−3.9%
Energy transition and decarbonisation942%98%0.60%0.60%6 of 8+20.5%
Gaming, esports and betting813%100%0.60%0.60%0 of 7−19.2%
Travel and leisure335%99%0.70%0.70%0 of 2−11.3%
Timber and forestry219%100%0.60%0.60%0 of 2−2.2%
Metaverse and immersive tech446%77%0.60%0.80%1 of 4+9.2%
Stablecoins and tokenisation518%98%0.70%0.70%1 of 2+11.9%
Photonics and optics327%100%0.80%0.80%0 of 0·
Humanoid robots315%94%0.60%0.60%0 of 2+3.8%
Healthcare innovation and GLP-1833%98%0.60%0.60%5 of 8+26.1%
Millennial and Gen Z consumers166%84%0.50%0.60%0 of 1−15.0%
Longevity and aging255%96%0.50%0.50%0 of 1+14.0%
Coal10%100%0.80%0.80%0 of 1+12.5%
3D printing127%99%0.70%0.70%0 of 1+7.8%
Streaming and live entertainment419%99%0.80%0.80%0 of 2−22.8%
Pets132%99%0.50%0.50%0 of 1−12.9%
Cooling and thermal management156%98%1.00%1.00%0 of 1+13.2%
Nanotechnology119%94%0.60%0.60%1 of 1+56.3%
Beauty and personal care147%99%0.30%0.30%0 of 0·
AI labs and single company AI6··0.60%·0 of 0·

Same portfolio, two names: pairs more than half identical

PairWeight overlapThemeFee, firstFee, second
PDBA and EVMT98%Agriculture0.59%0.59%
AUAU and GDX83%Gold miners0.35%0.51%
SOXQ and SOXX82%Semiconductors0.19%0.33%
ORBX and MARS82%Space0.50%0.75%
SHOC and SMH78%Semiconductors0.40%0.35%
ORBX and WARP78%Space0.50%0.50%
GDX and GDMN77%Gold miners0.51%0.45%
FTXL and SOXX77%Semiconductors0.60%0.33%
SPAM and PSWD76%Cybersecurity0.35%0.20%
FIW and PHO76%Water0.50%0.59%
MARS and WARP75%Space0.75%0.50%
BUG and WCBR75%Cybersecurity0.50%0.45%
AUAU and GDMN75%Gold miners0.35%0.45%
SOXQ and SMH74%Semiconductors0.19%0.35%
SOXQ and SHOC74%Semiconductors0.19%0.40%
Method

Holdings from each fund’s latest public SEC N-PORT filing (issuer daily files for ARK and First Trust); in-index weight and active share computed by ETFIQ against the IVV and QQQM books; fees from prospectus XBRL; returns from Tiingo end-of-day prices with distributions reinvested. Themes are ETFIQ’s editorial taxonomy. Medians across funds. Rebuilt every trading night.

Data file: thematic.json. ETFIQ is an independent publisher and makes no recommendations. Standards →

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Cite this page

ETFIQ Research, How much of a theme is already the index, data as of Sep 28, 2026. https://etfiq.com/research/2026-09-28/themes-index

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Free to use with attribution; the underlying files are at Open data.