IBB vs RGEN: Correlation
Measured on weekly returns over the past three years, iShares Biotechnology ETF (IBB) and Repligen Corporation (RGEN) carry a correlation of 0.64, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and RGEN?
Over the past 3 years, IBB and RGEN moved with a correlation of 0.64, which is strong. Recent behaviour matches the longer record: 0.67 over 1 year against 0.64 over 3. Over 5 years the correlation is 0.67, and the annualized covariance of weekly returns is 654.7 %².
Within IBB's tracked universe of 168 assets, RGEN comes in at #16 by 3-year correlation. Neither side won the trailing year by much: +55.4% against +53.1%. Risk is not evenly split, since RGEN carries 2.4 times the volatility of the other side.
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 RGEN: side by side
| IBB (iShares Biotechnology ETF) | RGEN (Repligen Corporation) | |
|---|---|---|
| 1-year return | +55.4% | +53.1% |
| 5-year return | +26.6% | -35.6% |
| Volatility (ann.) | 20.7% | 49.5% |
| Beta vs S&P 500 | 0.81 | 1.35 |
| Max drawdown (3Y) | -24.9% | -50.6% |
| Market cap | – | $10.3B |
| P/E (trailing) | – | 252.8 |
| Dividend yield | 0.22% | 0.00% |
| Expense ratio | 0.44% | – |
| Assets under management | $9.2B | – |
| Sector / category | ETF · Thematic | US Listed |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | IBB | RGEN |
|---|---|---|
| 2022 | -13.7% | -36.1% |
| 2023 | +3.8% | +6.2% |
| 2024 | -2.4% | -19.9% |
| 2025 | +28.0% | +13.8% |
| 2026 | +27.4% | +11.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
RGEN represents 0.66% of IBB's portfolio, so part of any move in IBB is RGEN itself, and the correlation between them is partly mechanical.
Are IBB and RGEN good diversifiers for each other?
Somewhat, no more. With 0.64 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between IBB and RGEN?
Using weekly returns as of 2026-08-27: 0.64 over 3 years, with 0.67 over the last year and 0.67 over 5 years.
Is RGEN a good diversifier for IBB?
Somewhat, no more. With 0.64 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.64 mean?
A reading of 0.64 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-rgen.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-rgen/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: IBB correlations · RGEN correlations
