How much of a theme is already the index
By their latest holdings filings, the typical thematic ETF has 32% of its weight in stocks the S&P 500 already holds, and 55 of 244 funds are more than sixty percent index names.
Across 27 themes and 285 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%.
94 pairs of funds hold portfolios that are more than half identical by weight; holding both is close to holding one of them twice.
Thematic ETFs are sold as a way to concentrate on a single idea, but the holdings often tell a more mixed story. Across 244 funds, the typical thematic ETF carries 32% of its weight in stocks the S&P 500 already holds, and 55 of those funds are more than sixty percent index names by weight. In other words, a meaningful slice of many theme portfolios overlaps with a benchmark investors may already hold elsewhere.
The overlap varies widely by theme. Semiconductors shows the highest median share tied to the S&P 500 at 81%, alongside a median active share of 82% across its 9 funds, all 9 of which beat the S&P 500 over one year, with a median total return of +105.4%. Digital infrastructure and data centers follows at 64% in the S&P 500. At the other end, electric vehicles and batteries sits at 9%, cannabis at 0%, and space at 14%, meaning these themes hold portfolios that diverge far more from the standard index.
Fees sit at a median of 0.60% across 285 funds spanning 27 themes. When the fee is measured only against the part of each portfolio that differs from the S&P 500, the median for that difference is also 0.60%, based on the summary figure. At the theme level this comparison shifts fund by fund: semiconductors charges a median fee of 0.30% but 0.40% on the differentiated slice, while artificial intelligence runs 0.70% against 0.80%, and clean energy holds steady at 0.60% either way.
Performance also varies by theme. Infrastructure, internet and e-commerce, water, cannabis, fintech and digital payments, and gaming, esports and betting each show 0 funds beating the S&P 500 over one year, while genomics and biotech innovation posted 3 of 4 beating it with a median total return of +73.1%, and electrification and the grid posted 9 of 11 with +67.9%.
Separately from index overlap, 94 pairs of funds across the full dataset hold portfolios that are more than half identical to each other by weight, meaning holding both is close to holding one of them twice. The closest pairs sit in semiconductors, where SOXQ and SOXX overlap 83% and carry fees of 0.19% and 0.33%, and SHOC and SMH overlap 82% with fees of 0.40% and 0.35%. Similar patterns appear in cybersecurity, where SPAM and PSWD overlap 76% with fees of 0.35% and 0.20%, and in blockchain and crypto equities, where several pairs including BKCH and DAPP, WGMI and MNRS, and BITQ and DAPP each show overlaps above 70% with differing fee levels attached to nearly identical exposure.
On the live desk, a reader can look up any individual fund's current in-index weight, active share, and fee against its named overlap partner to see how much of that specific theme is already captured by a broad index fund today.
By theme, largest assets first
| Theme | Funds | Median in the S&P 500 | Median active share | Median fee | Median fee for the difference | Beat the S&P 500, one year | Median total return, one year |
|---|---|---|---|---|---|---|---|
| Semiconductors | 9 | 81% | 82% | 0.30% | 0.40% | 9 of 9 | +105.4% |
| Defense | 19 | 35% | 98% | 0.50% | 0.50% | 1 of 11 | +9.2% |
| Artificial intelligence | 47 | 60% | 81% | 0.70% | 0.80% | 20 of 26 | +37.9% |
| Electrification and the grid | 14 | 27% | 99% | 0.60% | 0.60% | 9 of 11 | +67.9% |
| Cybersecurity | 7 | 33% | 99% | 0.50% | 0.50% | 6 of 7 | +25.4% |
| Infrastructure | 9 | 33% | 97% | 0.50% | 0.50% | 0 of 7 | +16.5% |
| Cloud and software | 8 | 45% | 92% | 0.40% | 0.40% | 2 of 7 | +8.8% |
| Nuclear and uranium | 9 | 15% | 100% | 0.70% | 0.70% | 1 of 8 | +10.2% |
| Broad innovation and megatrends | 31 | 51% | 86% | 0.50% | 0.60% | 15 of 29 | +21.8% |
| Internet and e-commerce | 14 | 29% | 95% | 0.70% | 0.70% | 0 of 14 | −12.6% |
| Robotics and automation | 12 | 17% | 94% | 0.70% | 0.70% | 6 of 8 | +22.9% |
| Clean energy | 17 | 10% | 99% | 0.60% | 0.60% | 10 of 15 | +26.4% |
| Quantum computing | 3 | 36% | 84% | 0.50% | 0.50% | 1 of 1 | +56.1% |
| Water | 7 | 38% | 100% | 0.50% | 0.60% | 0 of 6 | −4.0% |
| Space | 8 | 14% | 99% | 0.80% | 0.80% | 2 of 2 | +27.0% |
| Digital infrastructure and data centers | 8 | 64% | 94% | 0.50% | 0.50% | 5 of 7 | +39.1% |
| Blockchain and crypto equities | 12 | 18% | 98% | 0.60% | 0.70% | 6 of 12 | +19.2% |
| Electric vehicles and batteries | 13 | 9% | 98% | 0.50% | 0.50% | 7 of 11 | +33.0% |
| Genomics and biotech innovation | 4 | 18% | 98% | 0.50% | 0.50% | 3 of 4 | +73.1% |
| Cannabis | 4 | 0% | 100% | 0.80% | 0.80% | 0 of 4 | +4.5% |
| Food and agriculture | 6 | 36% | 100% | 0.60% | 0.50% | 4 of 5 | +21.4% |
| Fintech and digital payments | 4 | 42% | 94% | 0.70% | 0.80% | 0 of 4 | −15.0% |
| Gaming, esports and betting | 7 | 16% | 100% | 0.60% | 0.60% | 0 of 7 | −16.3% |
| Metaverse and immersive tech | 4 | 46% | 78% | 0.60% | 0.80% | 1 of 4 | +12.9% |
| Healthcare innovation and GLP-1 | 5 | 27% | 99% | 0.50% | 0.60% | 3 of 5 | +21.5% |
| Longevity and aging | 1 | 45% | 95% | 0.50% | 0.50% | 0 of 1 | +10.6% |
| Pets and consumer themes | 3 | 18% | 99% | 0.50% | 0.50% | 0 of 2 | −14.4% |
Same portfolio, two names: pairs more than half identical
| Pair | Weight overlap | Theme | Fee, first | Fee, second |
|---|---|---|---|---|
| SOXQ and SOXX | 83% | Semiconductors | 0.19% | 0.33% |
| SHOC and SMH | 82% | Semiconductors | 0.40% | 0.35% |
| FTXL and SOXQ | 78% | Semiconductors | 0.60% | 0.19% |
| SPAM and PSWD | 76% | Cybersecurity | 0.35% | 0.20% |
| SMH and SOXX | 74% | Semiconductors | 0.35% | 0.33% |
| BUG and WCBR | 74% | Cybersecurity | 0.50% | 0.45% |
| BKCH and DAPP | 72% | Blockchain and crypto equities | 0.50% | 0.52% |
| WGMI and MNRS | 71% | Blockchain and crypto equities | 0.75% | 0.59% |
| WEED and UX | 71% | Cannabis | 0.41% | 0.77% |
| WDEF and XDEF | 71% | Defense | 0.45% | 0.35% |
| BITQ and DAPP | 71% | Blockchain and crypto equities | 0.85% | 0.52% |
| BITQ and BKCH | 71% | Blockchain and crypto equities | 0.85% | 0.50% |
| SHOC and SOXX | 70% | Semiconductors | 0.40% | 0.33% |
| HERO and NERD | 70% | Gaming, esports and betting | 0.50% | 0.50% |
| FIW and PHO | 70% | Water | 0.50% | 0.59% |
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. Data file: https://etfiq.com/data/thematic.json. Rebuilt every trading night. ETFIQ is an independent publisher and makes no recommendations. Standards