IWM vs MLM: Correlation
How closely do iShares Russell 2000 ETF (IWM) and Martin Marietta Materials (MLM) trade together? Their weekly returns over three years give a correlation of 0.59, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IWM and MLM?
Across a 3-year window, the weekly returns of IWM and MLM correlate at 0.59, moderate. Recent behaviour matches the longer record: 0.55 over 1 year against 0.59 over 3. Stretching to 5 years gives 0.65, with an annualized covariance of 282.2 %².
Among the 320 assets we track against IWM, MLM ranks #133 by 3-year correlation. Correlation aside, the last 12 months split them widely, with IWM ahead by 42.2 points (+28.4% versus -13.8%). The link looks structural: the rolling one-year correlation barely moved, holding between 0.50 and 0.72.
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 MLM: side by side
| IWM (iShares Russell 2000 ETF) | MLM (Martin Marietta Materials) | |
|---|---|---|
| 1-year return | +28.4% | -13.8% |
| 5-year return | +41.5% | +42.4% |
| Volatility (ann.) | 19.8% | 23.9% |
| Beta vs S&P 500 | 1.06 | 0.85 |
| Max drawdown (3Y) | -27.5% | -26.8% |
| Market cap | – | $37.5B |
| P/E (trailing) | – | 34.4 |
| Dividend yield | 0.91% | 0.62% |
| Expense ratio | 0.19% | – |
| Assets under management | $80.1B | – |
| Sector / category | ETF · US Small & Mid Cap | Materials |
On the fund side, IWM sits in the Small Blend category at iShares, with $80.1B under management, 1757 holdings, a 0.19% expense ratio, a 0.91% trailing dividend yield.
Year-by-year returns
| Year | IWM | MLM |
|---|---|---|
| 2022 | -20.5% | -22.7% |
| 2023 | +16.8% | +48.6% |
| 2024 | +11.4% | +4.1% |
| 2025 | +12.7% | +21.3% |
| 2026 | +22.3% | -14.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IWM and MLM good diversifiers for each other?
Somewhat, no more. With 0.59 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between IWM and MLM?
As of 2026-08-27, the correlation of weekly returns between IWM and MLM is 0.59 over 3 years, 0.55 over 1 year and 0.65 over 5 years.
Is MLM a good diversifier for IWM?
Somewhat, no more. With 0.59 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.59 mean?
A reading of 0.59 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/iwm-vs-mlm.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/iwm-vs-mlm/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IWM correlations · MLM correlations
