Data as of .
FDN vs IDEF: which is really different?
FDN holds 82.4% 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, FDN and IDEF hold 0% of their money in the same securities at the same weight.
| Only in FDN | Only in IDEF |
|---|---|
| Meta Platforms, Inc. (Class A) 10.43% | RTX 6.72% |
| Amazon.com, Inc. 9.78% | PALANTIR TECHNOLOGIES CLASS A 4.71% |
| Cisco Systems, Inc. 7.25% | LOCKHEED MARTIN CORP 3.62% |
| Salesforce, Inc. 5.91% | BOEING 3.32% |
| Arista Networks, Inc. 5.18% | ROLLS-ROYCE HOLDINGS PLC 3.30% |
| Alphabet Inc. (Class A) 4.79% | GENERAL DYNAMICS CORP 2.97% |
| Booking Holdings Inc. 4.51% | USD CASH 2.72% |
| Oracle Corporation 4.44% | THALES SA 2.61% |
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 | |||
|---|---|---|---|---|---|---|
| FDN | IDEF | FDN | IDEF | FDN | IDEF | |
| 3 months | +9.3% | −1.9% | +6.0 pts | −5.2 pts | +10.1 pts | −1.1 pts |
| 6 months | +20.3% | −8.5% | +4.3 pts | −24.5 pts | −0.4 pts | −29.2 pts |
| 1 year | +1.9% | +4.9% | −15.6 pts | −12.6 pts | −21.0 pts | −18.1 pts |
| 3 years | +69.5% | not published | −8.4 pts | not published | −25.6 pts | not published |
| Since launch | +1031.5% | +26.5% | +227.1 pts | −6.4 pts | −642.4 pts | −13.6 pts |
| FDN First Trust Dow Jones Internet Index Fund Holds 42 stocks in internet and e-commerce, 82% of its weight in S&P 500 companies | IDEF iShares Defense Industrials Active ETF Holds 152 stocks in defense, 36% of its weight in S&P 500 companies | |
|---|---|---|
| Issuer | First Trust | iShares |
| Theme | Internet and e-commerce | Defense |
| In the S&P 500 | 82.4% | 36.1% |
| Active share vs the S&P 500 | 85.5% | 95.9% |
| In the Nasdaq-100 | 57.1% | 8.5% |
| Holdings | 42 | 152 |
| Top ten, share of the fund | 60.5% | 35.2% |
| Expense ratio | 0.49% | not published |
| Fee for the differing part | 0.57% | not published |
| Total return, 1 year | +1.9% | +4.9% |
| vs the S&P 500 | −15.6 pts | −12.6 pts |
| vs the Nasdaq-100 | −21.0 pts | −18.1 pts |
| Below its high | −2.1% | −13.9% |
FDN in plain words
By weight, 82% of FDN's portfolio is stocks that are also in the S&P 500; its active share against the S&P 500 is 86%. The top ten holdings are 60% of the fund across 42 positions, as published by its issuer for Sep 10, 2026. Over the year to Sep 11, 2026 the fund returned +1.9% with distributions reinvested against +17.5% for the S&P 500, so a holder was behind by 15.6 pts.
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.
Questions people ask
- Which is more different from the S&P 500, FDN or IDEF?
- FDN has 82% of its weight in S&P 500 names and IDEF has 36%, 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, FDN against IDEF, data as of Sep 11, 2026. https://etfiq.com/compare/themes/fdn-vs-idef Free to use with attribution; the underlying files are at Open data.