Data as of .
IDEF vs MISL: which is really different?
IDEF and MISL hold 37% of their weight in the same names, and MISL returned more over the year.
ETFIQ Off-Index Score: MISL scores higher
How much of it is not the index it is sold as an alternative to?
A percentile among the 379 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
37% of the two portfolios are the same securities at the same weight.
What they hold in common
By the books each fund has filed, IDEF and MISL hold 37% of their money in the same securities at the same weight.
| Holding | IDEF | MISL |
|---|---|---|
| RTX | 6.55% | 8.30% |
| PALANTIR TECHNOLOGIES CLASS A | 5.02% | 11.75% |
| LOCKHEED MARTIN CORP | 3.62% | 4.27% |
| BOEING | 3.19% | 7.48% |
| GENERAL DYNAMICS CORP | 2.94% | 3.95% |
| NORTHROP GRUMMAN CORP | 2.58% | 4.10% |
| SPACE EXPLORATION TECHNOLOGIES COR | 2.44% | 8.81% |
| GE AEROSPACE | 1.83% | 7.34% |
| TRANSDIGM GROUP | 1.01% | 3.53% |
| HOWMET AEROSPACE | 0.70% | 3.56% |
| ROCKET LAB CORP | 0.70% | 3.34% |
| AIRBUS GROUP | 2.55% | 0.51% |
| Only in IDEF | Only in MISL |
|---|---|
| BLK CSH FND TREASURY SL AGENCY 3.77% | AST SpaceMobile, Inc. 2.56% |
| ROLLS-ROYCE HOLDINGS PLC 3.29% | FTAI Aviation Ltd. 2.21% |
| HANWHA AEROSPACE LTD 2.21% | CACI International Inc. 1.56% |
| BAE SYSTEMS PLC 2.18% | Moog Inc. 1.31% |
| THALES SA 2.18% | Loar Holdings Inc. 0.68% |
| MITSUBISHI HEAVY INDUSTRIES 1.73% | Firefly Aerospace Inc. 0.39% |
| HANWHA SYSTEMS LTD 1.69% | Intuitive Machines, Inc. (Class A) 0.34% |
| PALO ALTO NETWORKS 1.66% | Astronics Corporation 0.32% |
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 18, 2026.
Performance, window by window
| Window | Total return | vs the S&P 500 | vs the Nasdaq-100 | |||
|---|---|---|---|---|---|---|
| IDEF | MISL | IDEF | MISL | IDEF | MISL | |
| 3 months | −1.6% | −8.7% | −3.9 pts | −10.9 pts | +0.9 pts | −6.2 pts |
| 6 months | −5.7% | −7.5% | −23.8 pts | −25.5 pts | −30.0 pts | −31.7 pts |
| 1 year | +4.4% | +6.4% | −12.2 pts | −10.2 pts | −17.4 pts | −15.4 pts |
| 3 years | not published | +93.1% | not published | +14.7 pts | not published | −5.1 pts |
| Since launch | +27.2% | +109.5% | −5.6 pts | −0.6 pts | −14.2 pts | −56.0 pts |
| IDEF iShares Defense Industrials Active ETF Holds 155 stocks in defense, 36% of its weight in S&P 500 companies | MISL First Trust Indxx Aerospace & Defense ETF Holds 40 stocks in defense, 62% of its weight in S&P 500 companies | |
|---|---|---|
| Issuer | iShares | First Trust |
| Theme | Defense | Defense |
| In the S&P 500 | 36.2% | 62.4% |
| Active share vs the S&P 500 | 95.9% | 97.5% |
| In the Nasdaq-100 | 9.2% | 11.8% |
| Holdings | 155 | 40 |
| Top ten, share of the fund | 35.8% | 63.1% |
| Expense ratio | not published | 0.60% |
| Fee for the differing part | not published | 0.62% |
| Total return, 1 year | +4.4% | +6.4% |
| vs the S&P 500 | −12.2 pts | −10.2 pts |
| vs the Nasdaq-100 | −17.4 pts | −15.4 pts |
| Below its high | −13.4% | −16.9% |
| Net assets | $4.3bn | $704m |
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 36% of the fund across 155 positions, as published by its issuer for Sep 18, 2026. Over the year to Sep 18, 2026 the fund returned +4.4% with distributions reinvested against +16.6% for the S&P 500, so a holder was behind by 12.2 pts. It sits 13.4% below its all-time high of Mar 2, 2026.
MISL in plain words
By weight, 62% of MISL's portfolio is stocks that are also in the S&P 500; its active share against the S&P 500 is 98%. The top ten holdings are 63% of the fund across 40 positions, as published by its issuer for Sep 18, 2026. Over the year to Sep 18, 2026 the fund returned +6.4% with distributions reinvested against +16.6% for the S&P 500, so a holder was behind by 10.2 pts. It sits 16.9% below its all-time high of Jan 16, 2026.
Questions people ask
- Do IDEF and MISL hold the same stocks?
- By their latest filings, 37% of their books are the same securities at the same weight, which is a meaningful overlap. Overlap is the sum of the smaller weight of every security they share.
- Which is more different from the S&P 500, IDEF or MISL?
- IDEF has 36% of its weight in S&P 500 names and MISL has 62%, so MISL 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 MISL, data as of Sep 18, 2026. https://etfiq.com/compare/themes/idef-vs-misl Free to use with attribution; the underlying files are at Open data.