ACA vs IWM: Correlation
Measured on weekly returns over the past three years, Arcosa, Inc. (ACA) and iShares Russell 2000 ETF (IWM) carry a correlation of 0.71, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ACA and IWM?
Across a 3-year window, the weekly returns of ACA and IWM correlate at 0.71, strong. The link has loosened recently: the 1-year correlation (0.47) runs below the 3-year figure (0.71). Stretching to 5 years gives 0.64, with an annualized covariance of 449.9 %².
In ACA's tracked universe of 23 assets, IWM sits right near the top at #1. Correlation aside, the last 12 months split them widely, with ACA ahead by 18.6 points (+47.0% versus +28.4%). One caveat on sizing: ACA is 1.6 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.
ACA vs IWM: side by side
| ACA (Arcosa, Inc.) | IWM (iShares Russell 2000 ETF) | |
|---|---|---|
| 1-year return | +47.0% | +28.4% |
| 5-year return | +186.5% | +41.5% |
| Volatility (ann.) | 31.9% | 19.8% |
| Beta vs S&P 500 | 1.23 | 1.06 |
| Max drawdown (3Y) | -36.6% | -27.5% |
| Market cap | $7.1B | – |
| P/E (trailing) | 32.5 | – |
| Dividend yield | 0.14% | 0.91% |
| Expense ratio | – | 0.19% |
| Assets under management | – | $80.1B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
IWM, iShares's Small Blend fund, carries $80.1B under management, 1757 holdings, a 0.19% expense ratio, a 0.91% trailing dividend yield.
Year-by-year returns
| Year | ACA | IWM |
|---|---|---|
| 2022 | +3.5% | -20.5% |
| 2023 | +52.5% | +16.8% |
| 2024 | +17.3% | +11.4% |
| 2025 | +10.2% | +12.7% |
| 2026 | +37.0% | +22.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
ACA represents 0.23% of IWM's portfolio, so part of any move in IWM is ACA itself, and the correlation between them is partly mechanical.
Are ACA and IWM good diversifiers for each other?
To a limited degree. At 0.71 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between ACA and IWM?
Using weekly returns as of 2026-08-27: 0.71 over 3 years, with 0.47 over the last year and 0.64 over 5 years.
Is IWM a good diversifier for ACA?
To a limited degree. At 0.71 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.71 mean?
A reading of 0.71 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/aca-vs-iwm.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/aca-vs-iwm/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ACA correlations · IWM correlations
