IBB vs ICLN: Correlation & Overlap
How closely do iShares Biotechnology ETF (IBB) and iShares Global Clean Energy ETF (ICLN) trade together? Their weekly returns over three years give a correlation of 0.38, which is moderate. By holdings, the two funds overlap 0% by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and ICLN?
On 3 years of weekly data the IBB/ICLN correlation comes out at 0.38, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.13 versus 0.38 over 3 years. The 5-year figure is 0.47, and annualized covariance runs at 187.2 %².
By 3-year correlation, ICLN places #151 of the 168 assets tracked against IBB. Correlation aside, the last 12 months split them widely, with IBB ahead by 29.8 points (+55.4% versus +25.6%). Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from 0.17 to 0.72.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
IBB vs ICLN: side by side
| IBB (iShares Biotechnology ETF) | ICLN (iShares Global Clean Energy ETF) | |
|---|---|---|
| 1-year return | +55.4% | +25.6% |
| 5-year return | +26.6% | -18.4% |
| Volatility (ann.) | 20.7% | 24.0% |
| Beta vs S&P 500 | 0.81 | 0.78 |
| Max drawdown (3Y) | -24.9% | -34.6% |
| Dividend yield | 0.22% | 1.05% |
| Expense ratio | 0.44% | 0.39% |
| Assets under management | $9.2B | $2.3B |
| Sector / category | ETF · Thematic | ETF · Thematic |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. ICLN, iShares's Miscellaneous Sector fund, carries $2.3B under management, 102 holdings, a 0.39% expense ratio, a 1.05% trailing dividend yield.
Portfolio overlap between IBB and ICLN
The two portfolios are largely distinct, with 0 holdings in common adding up to 0% of fund weight. Where correlation shows the co-movement, the overlap shows its source.
Largest positions held only by IBB: AMGN (8.43%), VRTX (7.89%), GILD (7.10%), REGN (5.68%), MRNA (3.76%). Only by ICLN: FSLR (7.87%), 600900 (7.64%), BE (7.36%), NXT (6.81%), ENPH (4.70%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26.
Year-by-year returns
| Year | IBB | ICLN |
|---|---|---|
| 2022 | -13.7% | -5.4% |
| 2023 | +3.8% | -20.4% |
| 2024 | -2.4% | -25.7% |
| 2025 | +28.0% | +47.0% |
| 2026 | +27.4% | +8.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and ICLN good diversifiers for each other?
Reasonably. At 0.38, IBB and ICLN keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between IBB and ICLN?
As of 2026-08-27, the correlation of weekly returns between IBB and ICLN is 0.38 over 3 years, 0.13 over 1 year and 0.47 over 5 years.
Is ICLN a good diversifier for IBB?
Reasonably. At 0.38, IBB and ICLN keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
How much do IBB and ICLN overlap?
The two funds share 0 holdings amounting to 0% of weight, per issuer portfolio files dated 2026-08-26.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-icln.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/ibb-vs-icln/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IBB correlations · ICLN correlations
