CTOS vs IWM: Correlation
Custom Truck One Source, Inc. (CTOS) and iShares Russell 2000 ETF (IWM) show a moderate relationship: their 3-year correlation of weekly returns is 0.59.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CTOS and IWM?
Across a 3-year window, the weekly returns of CTOS and IWM correlate at 0.59, moderate. The relationship has been stable: the 1-year correlation (0.53) sits close to the 3-year figure. Stretching to 5 years gives 0.61, with an annualized covariance of 633.7 %².
IWM is one of the assets that tracks CTOS most closely: it ranks #1 out of the 13 assets we track against CTOS. Their recent paths diverged sharply: over the last 12 months CTOS outperformed by 32.9 percentage points (+61.3% for CTOS against +28.4% for IWM). One caveat on sizing: CTOS is 2.7 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.
CTOS vs IWM: side by side
| CTOS (Custom Truck One Source, Inc.) | IWM (iShares Russell 2000 ETF) | |
|---|---|---|
| 1-year return | +61.3% | +28.4% |
| 5-year return | +8.1% | +41.5% |
| Volatility (ann.) | 54.4% | 19.8% |
| Beta vs S&P 500 | 1.42 | 1.06 |
| Max drawdown (3Y) | -55.6% | -27.5% |
| Market cap | $2.2B | – |
| P/E (trailing) | 107.3 | – |
| Dividend yield | 0.00% | 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 | CTOS | IWM |
|---|---|---|
| 2022 | -21.0% | -20.5% |
| 2023 | -2.2% | +16.8% |
| 2024 | -22.2% | +11.4% |
| 2025 | +19.8% | +12.7% |
| 2026 | +67.7% | +22.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CTOS and IWM good diversifiers for each other?
Only partially. A correlation of 0.59 means CTOS and IWM 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 CTOS and IWM?
Using weekly returns as of 2026-08-27: 0.59 over 3 years, with 0.53 over the last year and 0.61 over 5 years.
Is IWM a good diversifier for CTOS?
Only partially. A correlation of 0.59 means CTOS and IWM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.59 mean?
On the −1 to +1 scale, 0.59 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ctos-vs-iwm.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ctos-vs-iwm/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: CTOS correlations · IWM correlations
