IBB vs MRK: Correlation
iShares Biotechnology ETF (IBB) and Merck & Co. (MRK) show a moderate relationship: their 3-year correlation of weekly returns is 0.56.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and MRK?
On 3 years of weekly data the IBB/MRK correlation comes out at 0.56, moderate. The relationship has been stable: the 1-year correlation (0.57) sits close to the 3-year figure. The 5-year figure is 0.40, and annualized covariance runs at 322.8 %².
Among the 168 assets we track against IBB, MRK ranks #58 by 3-year correlation. The last year tells two different stories: MRK led by 28.4 percentage points, +55.4% for IBB against +83.8% for MRK. This link changes with the market regime, having swung between 0.04 and 0.76 on a rolling one-year basis.
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 MRK: side by side
| IBB (iShares Biotechnology ETF) | MRK (Merck & Co.) | |
|---|---|---|
| 1-year return | +55.4% | +83.8% |
| 5-year return | +26.6% | +128.5% |
| Volatility (ann.) | 20.7% | 27.9% |
| Beta vs S&P 500 | 0.81 | 0.28 |
| Max drawdown (3Y) | -24.9% | -43.4% |
| Market cap | – | $368.9B |
| P/E (trailing) | – | 121.6 |
| Dividend yield | 0.22% | 2.17% |
| Expense ratio | 0.44% | – |
| Assets under management | $9.2B | – |
| Sector / category | ETF · Thematic | Health Care |
IBB is a Health fund from iShares: $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | IBB | MRK |
|---|---|---|
| 2022 | -13.7% | +49.4% |
| 2023 | +3.8% | +1.0% |
| 2024 | -2.4% | -6.3% |
| 2025 | +28.0% | +9.8% |
| 2026 | +27.4% | +44.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and MRK good diversifiers for each other?
Somewhat, no more. With 0.56 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between IBB and MRK?
The IBB/MRK correlation stands at 0.56 on a 3-year window (1 year: 0.57, 5 years: 0.40), computed from weekly returns as of 2026-08-27.
Is MRK a good diversifier for IBB?
Somewhat, no more. With 0.56 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.56 mean?
On the −1 to +1 scale, 0.56 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-mrk.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-mrk/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IBB correlations · MRK correlations
