Data as of .
IDEF vs SOXX: which is really different?
SOXX holds 73.8% of its weight in S&P 500 companies and IDEF 36.1%.
ETFIQ Off-Index Score: IDEF scores higher
How much of it is not the index it is sold as an alternative to?
A percentile among the 371 thematic ETFs with a holdings filing. It is a position in a set, not a rating, and neither end of it is a recommendation. All thematic ETFs ranked by it · How it is computed
What they hold in common
By the books each fund has filed, IDEF and SOXX hold 1% of their money in the same securities at the same weight.
| Holding | IDEF | SOXX |
|---|---|---|
| MACOM TECHNOLOGY SOLUTIONS | 0.64% | 1.04% |
| USD CASH | 2.72% | 0.04% |
| Only in IDEF | Only in SOXX |
|---|---|
| RTX 6.72% | NVIDIA 9.22% |
| PALANTIR TECHNOLOGIES CLASS A 4.71% | MICRON TECHNOLOGY 8.97% |
| LOCKHEED MARTIN CORP 3.62% | ADVANCED MICRO DEVICES 8.70% |
| BOEING 3.32% | BROADCOM INC 7.20% |
| ROLLS-ROYCE HOLDINGS PLC 3.30% | INTEL CORPORATION 5.64% |
| GENERAL DYNAMICS CORP 2.97% | MARVELL TECHNOLOGY 4.93% |
| THALES SA 2.61% | TAIWAN SEMICONDUCTOR MANUFACTURING 4.74% |
| NORTHROP GRUMMAN CORP 2.56% | APPLIED MATERIAL INC 4.50% |
Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Sep 10, 2026.
Performance, window by window
| Window | Total return | vs the S&P 500 | vs the Nasdaq-100 | |||
|---|---|---|---|---|---|---|
| IDEF | SOXX | IDEF | SOXX | IDEF | SOXX | |
| 3 months | −1.9% | −11.6% | −5.2 pts | −14.9 pts | −1.1 pts | −10.8 pts |
| 6 months | −8.5% | +59.3% | −24.5 pts | +43.2 pts | −29.2 pts | +38.6 pts |
| 1 year | +4.9% | +107.5% | −12.6 pts | +90.0 pts | −18.1 pts | +84.5 pts |
| 3 years | not published | +229.6% | not published | +151.7 pts | not published | +134.5 pts |
| Since launch | +26.5% | +3687.1% | −6.4 pts | +2882.7 pts | −13.6 pts | +2013.2 pts |
| IDEF iShares Defense Industrials Active ETF Holds 152 stocks in defense, 36% of its weight in S&P 500 companies | SOXX iShares Semiconductor ETF Holds 32 stocks in semiconductors, 74% of its weight in S&P 500 companies | |
|---|---|---|
| Issuer | iShares | iShares |
| Theme | Defense | Semiconductors |
| In the S&P 500 | 36.1% | 73.8% |
| Active share vs the S&P 500 | 95.9% | 82.3% |
| In the Nasdaq-100 | 8.5% | 65.2% |
| Holdings | 152 | 32 |
| Top ten, share of the fund | 35.2% | 62.2% |
| Expense ratio | not published | 0.33% |
| Fee for the differing part | not published | 0.40% |
| Total return, 1 year | +4.9% | +107.5% |
| vs the S&P 500 | −12.6 pts | +90.0 pts |
| vs the Nasdaq-100 | −18.1 pts | +84.5 pts |
| Below its high | −13.9% | −19.5% |
IDEF in plain words
By weight, 36% of IDEF's portfolio is stocks that are also in the S&P 500; its active share against the S&P 500 is 96%. The top ten holdings are 35% of the fund across 152 positions, as published by its issuer for Sep 10, 2026. Over the year to Sep 11, 2026 the fund returned +4.9% with distributions reinvested against +17.5% for the S&P 500, so a holder was behind by 12.6 pts. It sits 13.9% below its all-time high of Mar 2, 2026.
SOXX in plain words
By weight, 74% of SOXX's portfolio is stocks that are also in the S&P 500; its active share against the S&P 500 is 82%. The top ten holdings are 62% of the fund across 32 positions, as published by its issuer for Sep 10, 2026. Over the year to Sep 11, 2026 the fund returned +107.5% with distributions reinvested against +17.5% for the S&P 500, so a holder was ahead by 90.0 pts. It sits 19.5% below its all-time high of Jun 22, 2026.
Questions people ask
- Which is more different from the S&P 500, IDEF or SOXX?
- IDEF has 36% of its weight in S&P 500 names and SOXX has 74%, so IDEF differs more from the index.
Other comparisons
Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, IDEF against SOXX, data as of Sep 11, 2026. https://etfiq.com/compare/themes/idef-vs-soxx Free to use with attribution; the underlying files are at Open data.