IWM vs ROCK: Correlation
How closely do iShares Russell 2000 ETF (IWM) and Gibraltar Industries, Inc. (ROCK) trade together? Their weekly returns over three years give a correlation of 0.63, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IWM and ROCK?
Over the past 3 years, IWM and ROCK moved with a correlation of 0.63, which is strong. Little has changed lately, as the 1-year reading of 0.57 lands near the 3-year figure. Over 5 years the correlation is 0.65, and the annualized covariance of weekly returns is 490.2 %².
Within IWM's tracked universe of 320 assets, ROCK comes in at #87 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IWM outperformed by 57.4 percentage points (+28.4% for IWM against -29.0% for ROCK). One caveat on sizing: ROCK is 2.0 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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 ROCK: side by side
| IWM (iShares Russell 2000 ETF) | ROCK (Gibraltar Industries, Inc.) | |
|---|---|---|
| 1-year return | +28.4% | -29.0% |
| 5-year return | +41.5% | -39.2% |
| Volatility (ann.) | 19.8% | 39.2% |
| Beta vs S&P 500 | 1.06 | 1.19 |
| Max drawdown (3Y) | -27.5% | -61.2% |
| Market cap | – | $1.4B |
| P/E (trailing) | – | 22.9 |
| 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 | ROCK |
|---|---|---|
| 2022 | -20.5% | -31.2% |
| 2023 | +16.8% | +72.1% |
| 2024 | +11.4% | -25.4% |
| 2025 | +12.7% | -16.1% |
| 2026 | +22.3% | -7.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IWM and ROCK good diversifiers for each other?
Somewhat, no more. With 0.63 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between IWM and ROCK?
The IWM/ROCK correlation stands at 0.63 on a 3-year window (1 year: 0.57, 5 years: 0.65), computed from weekly returns as of 2026-08-27.
Is ROCK a good diversifier for IWM?
Somewhat, no more. With 0.63 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.63 mean?
A reading of 0.63 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-rock.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/iwm-vs-rock/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: IWM correlations · ROCK correlations
