CTOS vs MDY: Correlation
Custom Truck One Source, Inc. (CTOS) and SPDR S&P MidCap 400 ETF (MDY) show a moderate relationship: their 3-year correlation of weekly returns is 0.56.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CTOS and MDY?
On 3 years of weekly data the CTOS/MDY correlation comes out at 0.56, moderate. The relationship has been stable: the 1-year correlation (0.54) sits close to the 3-year figure. The 5-year figure is 0.57, and annualized covariance runs at 502.4 %².
In CTOS's tracked universe of 13 assets, MDY sits right near the top at #3. Correlation aside, the last 12 months split them widely, with CTOS ahead by 43.0 points (+61.3% versus +18.3%). One caveat on sizing: CTOS is 3.3 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.
CTOS vs MDY: side by side
| CTOS (Custom Truck One Source, Inc.) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +61.3% | +18.3% |
| 5-year return | +8.1% | +47.5% |
| Volatility (ann.) | 54.4% | 16.5% |
| Beta vs S&P 500 | 1.42 | 0.91 |
| Max drawdown (3Y) | -55.6% | -24.0% |
| Market cap | $2.2B | – |
| P/E (trailing) | 107.3 | – |
| Dividend yield | 0.00% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
MDY, State Street Investment Management's Mid-Cap Blend fund, carries $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | CTOS | MDY |
|---|---|---|
| 2022 | -21.0% | -13.3% |
| 2023 | -2.2% | +16.1% |
| 2024 | -22.2% | +13.6% |
| 2025 | +19.8% | +7.2% |
| 2026 | +67.7% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CTOS and MDY good diversifiers for each other?
Only partially. A correlation of 0.56 means CTOS and MDY 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 MDY?
The CTOS/MDY correlation stands at 0.56 on a 3-year window (1 year: 0.54, 5 years: 0.57), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for CTOS?
Only partially. A correlation of 0.56 means CTOS and MDY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.56 mean?
A reading of 0.56 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
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Related comparisons
Hubs: CTOS correlations · MDY correlations
