IBB vs XLU: Correlation & Overlap
Measured on weekly returns over the past three years, iShares Biotechnology ETF (IBB) and Utilities Select Sector SPDR Fund (XLU) carry a correlation of 0.21, a weak link. The two funds also share 0% of their portfolios by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and XLU?
Across a 3-year window, the weekly returns of IBB and XLU correlate at 0.21, weak. The past 12 months show a weaker link (-0.01) than the 3-year average (0.21). Stretching to 5 years gives 0.32, with an annualized covariance of 67.7 %².
By 3-year correlation, XLU places #157 of the 168 assets tracked against IBB. Their recent paths diverged sharply: over the last 12 months IBB outperformed by 51.3 percentage points (+55.4% for IBB against +4.1% for XLU). Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from -0.00 to 0.54.
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 XLU: side by side
| IBB (iShares Biotechnology ETF) | XLU (Utilities Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | +55.4% | +4.1% |
| 5-year return | +26.6% | +46.3% |
| Volatility (ann.) | 20.7% | 15.8% |
| Beta vs S&P 500 | 0.81 | 0.26 |
| Max drawdown (3Y) | -24.9% | -13.1% |
| Dividend yield | 0.22% | 2.70% |
| Expense ratio | 0.44% | 0.08% |
| Assets under management | $9.2B | $23.1B |
| Sector / category | ETF · Thematic | Sector ETF |
On the fund side, IBB sits in the Health category at iShares, with $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. XLU is an Utilities fund from State Street Investment Management: $23.1B under management, 31 holdings, a 0.08% expense ratio, a 2.70% trailing dividend yield.
Portfolio overlap between IBB and XLU
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 XLU: NEE (12.94%), SO (7.45%), DUK (7.00%), CEG (6.58%), AEP (4.94%).
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 | XLU |
|---|---|---|
| 2022 | -13.7% | +1.4% |
| 2023 | +3.8% | -7.2% |
| 2024 | -2.4% | +23.3% |
| 2025 | +28.0% | +16.0% |
| 2026 | +27.4% | +2.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and XLU good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.21 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between IBB and XLU?
Using weekly returns as of 2026-08-27: 0.21 over 3 years, with -0.01 over the last year and 0.32 over 5 years.
Is XLU a good diversifier for IBB?
Yes, to a useful degree: a correlation of 0.21 leaves real independence between the two, which historically damped combined volatility.
How much do IBB and XLU overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 0% by weight over 0 common positions.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-xlu.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-xlu/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: IBB correlations · XLU correlations
