IBB vs IRON: Correlation
Measured on weekly returns over the past three years, iShares Biotechnology ETF (IBB) and Disc Medicine, Inc. (IRON) carry a correlation of 0.47, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and IRON?
Over the past 3 years, IBB and IRON moved with a correlation of 0.47, which is moderate. Little has changed lately, as the 1-year reading of 0.42 lands near the 3-year figure. Over 5 years the correlation is 0.35, and the annualized covariance of weekly returns is 585.8 %².
Among the 168 assets we track against IBB, IRON ranks #114 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IBB outperformed by 17.7 percentage points (+55.4% for IBB against +37.7% for IRON). Note the risk asymmetry: IRON runs 2.9 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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 IRON: side by side
| IBB (iShares Biotechnology ETF) | IRON (Disc Medicine, Inc.) | |
|---|---|---|
| 1-year return | +55.4% | +37.7% |
| 5-year return | +26.6% | -32.4% |
| Volatility (ann.) | 20.7% | 59.7% |
| Beta vs S&P 500 | 0.81 | 1.70 |
| Max drawdown (3Y) | -24.9% | -64.8% |
| Market cap | – | $3.2B |
| P/E (trailing) | – | – |
| Dividend yield | 0.22% | 0.00% |
| Expense ratio | 0.44% | – |
| Assets under management | $9.2B | – |
| Sector / category | ETF · Thematic | US Listed |
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 | IRON |
|---|---|---|
| 2022 | -13.7% | -77.2% |
| 2023 | +3.8% | +190.4% |
| 2024 | -2.4% | +9.8% |
| 2025 | +28.0% | +25.3% |
| 2026 | +27.4% | +4.0% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.16% of IBB is IRON itself, so the fund partly moves with the stock by construction.
Are IBB and IRON good diversifiers for each other?
Reasonably. At 0.47, IBB and IRON keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between IBB and IRON?
Using weekly returns as of 2026-08-27: 0.47 over 3 years, with 0.42 over the last year and 0.35 over 5 years.
Is IRON a good diversifier for IBB?
Reasonably. At 0.47, IBB and IRON keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.47 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-iron.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-iron/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IBB correlations · IRON correlations
