IWM vs TREX: Correlation
iShares Russell 2000 ETF (IWM) and Trex Company, Inc. (TREX) show a strong relationship: their 3-year correlation of weekly returns is 0.63.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IWM and TREX?
On 3 years of weekly data the IWM/TREX correlation comes out at 0.63, strong. Recent behaviour matches the longer record: 0.68 over 1 year against 0.63 over 3. The 5-year figure is 0.62, and annualized covariance runs at 569.6 %².
Among the 320 assets we track against IWM, TREX ranks #88 by 3-year correlation. The last year tells two different stories: IWM led by 55.7 percentage points, +28.4% for IWM against -27.3% for TREX. One caveat on sizing: TREX is 2.3 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 TREX: side by side
| IWM (iShares Russell 2000 ETF) | TREX (Trex Company, Inc.) | |
|---|---|---|
| 1-year return | +28.4% | -27.3% |
| 5-year return | +41.5% | -58.7% |
| Volatility (ann.) | 19.8% | 45.3% |
| Beta vs S&P 500 | 1.06 | 1.48 |
| Max drawdown (3Y) | -27.5% | -69.9% |
| Market cap | – | $4.7B |
| P/E (trailing) | – | 27.4 |
| 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, 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 | IWM | TREX |
|---|---|---|
| 2022 | -20.5% | -68.7% |
| 2023 | +16.8% | +95.6% |
| 2024 | +11.4% | -16.6% |
| 2025 | +12.7% | -49.2% |
| 2026 | +22.3% | +31.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IWM and TREX good diversifiers for each other?
Only partially. A correlation of 0.63 means IWM and TREX share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between IWM and TREX?
Using weekly returns as of 2026-08-27: 0.63 over 3 years, with 0.68 over the last year and 0.62 over 5 years.
Is TREX a good diversifier for IWM?
Only partially. A correlation of 0.63 means IWM and TREX share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.63 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-trex.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/iwm-vs-trex/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IWM correlations · TREX correlations
