IBB vs XLC: Correlation & Overlap
Measured on weekly returns over the past three years, iShares Biotechnology ETF (IBB) and Communication Services Select Sector SPDR Fund (XLC) carry a correlation of 0.44, a moderate 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 XLC?
Across a 3-year window, the weekly returns of IBB and XLC correlate at 0.44, moderate. The link has loosened recently: the 1-year correlation (0.29) runs below the 3-year figure (0.44). Stretching to 5 years gives 0.53, with an annualized covariance of 144.6 %².
By 3-year correlation, XLC places #132 of the 168 assets tracked against IBB. The last year tells two different stories: IBB led by 53.9 percentage points, +55.4% for IBB against +1.5% for XLC. The relationship is regime-dependent: the rolling one-year correlation swung between 0.14 and 0.69 over the past three years, so this pair behaves very differently depending on the market environment.
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 XLC: side by side
| IBB (iShares Biotechnology ETF) | XLC (Communication Services Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | +55.4% | +1.5% |
| 5-year return | +26.6% | +37.5% |
| Volatility (ann.) | 20.7% | 16.0% |
| Beta vs S&P 500 | 0.81 | 0.90 |
| Max drawdown (3Y) | -24.9% | -18.0% |
| Dividend yield | 0.22% | 1.32% |
| Expense ratio | 0.44% | 0.08% |
| Assets under management | $9.2B | $21.7B |
| Sector / category | ETF · Thematic | Sector ETF |
IBB is a Health fund from iShares: $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. On the fund side, XLC sits in the Communications category at State Street Investment Management, with $21.7B under management, 24 holdings, a 0.08% expense ratio, a 1.32% trailing dividend yield.
Portfolio overlap between IBB and XLC
The two portfolios are largely distinct: 0% of the funds' weight sits in the same underlying holdings (0 common positions). Correlation tells you they move together; overlap tells you why.
Largest positions held only by IBB: AMGN (8.43%), VRTX (7.89%), GILD (7.10%), REGN (5.68%), MRNA (3.76%). Only by XLC: META (16.73%), GOOGL (10.29%), GOOG (8.22%), T (5.20%), VZ (4.99%).
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 | XLC |
|---|---|---|
| 2022 | -13.7% | -37.6% |
| 2023 | +3.8% | +52.8% |
| 2024 | -2.4% | +34.7% |
| 2025 | +28.0% | +23.1% |
| 2026 | +27.4% | -4.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and XLC good diversifiers for each other?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between IBB and XLC?
Using weekly returns as of 2026-08-27: 0.44 over 3 years, with 0.29 over the last year and 0.53 over 5 years.
Is XLC a good diversifier for IBB?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
How much do IBB and XLC 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-xlc.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/ibb-vs-xlc/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: IBB correlations · XLC correlations
