IWM vs RMTI: Correlation
Measured on weekly returns over the past three years, iShares Russell 2000 ETF (IWM) and Rockwell Medical, Inc. (RMTI) carry a correlation of 0.38, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IWM and RMTI?
Across a 3-year window, the weekly returns of IWM and RMTI correlate at 0.38, moderate. The past 12 months show a weaker link (0.19) than the 3-year average (0.38). Stretching to 5 years gives 0.35, with an annualized covariance of 605.4 %².
Within IWM's tracked universe of 320 assets, RMTI comes in at #304 by 3-year correlation. The last year tells two different stories: IWM led by 75.7 percentage points, +28.4% for IWM against -47.3% for RMTI. Note the risk asymmetry: RMTI runs 4.0 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.
IWM vs RMTI: side by side
| IWM (iShares Russell 2000 ETF) | RMTI (Rockwell Medical, Inc.) | |
|---|---|---|
| 1-year return | +28.4% | -47.3% |
| 5-year return | +41.5% | -89.3% |
| Volatility (ann.) | 19.8% | 79.9% |
| Beta vs S&P 500 | 1.06 | 1.63 |
| Max drawdown (3Y) | -27.5% | -88.8% |
| Market cap | – | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.91% | 0.00% |
| Expense ratio | 0.19% | – |
| Assets under management | $80.1B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
IWM is a Small Blend fund from iShares: $80.1B under management, 1757 holdings, a 0.19% expense ratio, a 0.91% trailing dividend yield.
Year-by-year returns
| Year | IWM | RMTI |
|---|---|---|
| 2022 | -20.5% | -77.6% |
| 2023 | +16.8% | +87.1% |
| 2024 | +11.4% | +7.9% |
| 2025 | +12.7% | -59.3% |
| 2026 | +22.3% | -6.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IWM and RMTI good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.38 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between IWM and RMTI?
As of 2026-08-27, the correlation of weekly returns between IWM and RMTI is 0.38 over 3 years, 0.19 over 1 year and 0.35 over 5 years.
Is RMTI a good diversifier for IWM?
Yes, to a useful degree: a correlation of 0.38 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.38 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/iwm-vs-rmti.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/iwm-vs-rmti/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IWM correlations · RMTI correlations
