IBB vs XBI: Correlation
iShares Biotechnology ETF (IBB) and SPDR S&P Biotech ETF (XBI) show a very strong relationship: their 3-year correlation of weekly returns is 0.92.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and XBI?
Over the past 3 years, IBB and XBI moved with a correlation of 0.92, which is very strong, meaning they move nearly in lockstep. Recent behaviour matches the longer record: 0.90 over 1 year against 0.92 over 3. Over 5 years the correlation is 0.90, and the annualized covariance of weekly returns is 527.5 %².
XBI is one of the assets that tracks IBB most closely: it ranks #1 out of the 168 assets we track against IBB. The last year tells two different stories: XBI led by 31.8 percentage points, +55.4% for IBB against +87.2% for XBI. The rolling one-year correlation stayed in a tight band between 0.84 and 0.97 over the past three years, which points to a structural rather than episodic relationship.
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 XBI: side by side
| IBB (iShares Biotechnology ETF) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +55.4% | +87.2% |
| 5-year return | +26.6% | +28.6% |
| Volatility (ann.) | 20.7% | 27.7% |
| Beta vs S&P 500 | 0.81 | 1.09 |
| Max drawdown (3Y) | -24.9% | -33.0% |
| Dividend yield | 0.22% | – |
| Expense ratio | 0.44% | – |
| Assets under management | $9.2B | – |
| Sector / category | ETF · Thematic | ETF · Thematic |
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.
Year-by-year returns
| Year | IBB | XBI |
|---|---|---|
| 2022 | -13.7% | -25.9% |
| 2023 | +3.8% | +7.6% |
| 2024 | -2.4% | +1.0% |
| 2025 | +28.0% | +35.9% |
| 2026 | +27.4% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and XBI good diversifiers for each other?
No: a correlation of 0.92 means IBB and XBI tend to fall together, which is precisely when diversification is supposed to help.
FAQ
What is the correlation between IBB and XBI?
Using weekly returns as of 2026-08-27: 0.92 over 3 years, with 0.90 over the last year and 0.90 over 5 years.
Is XBI a good diversifier for IBB?
No: a correlation of 0.92 means IBB and XBI tend to fall together, which is precisely when diversification is supposed to help.
What does a correlation of 0.92 mean?
On the −1 to +1 scale, 0.92 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-xbi.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/ibb-vs-xbi/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: IBB correlations · XBI correlations
