CBT vs MDY: Correlation
Measured on weekly returns over the past three years, Cabot Corporation (CBT) and SPDR S&P MidCap 400 ETF (MDY) carry a correlation of 0.61, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CBT and MDY?
On 3 years of weekly data the CBT/MDY correlation comes out at 0.61, strong. The relationship has been stable: the 1-year correlation (0.53) sits close to the 3-year figure. The 5-year figure is 0.67, and annualized covariance runs at 287.2 %².
Within CBT's tracked universe of 15 assets, MDY comes in at #4 by 3-year correlation. The trailing year gives MDY the advantage: +5.7% versus +18.3%, a 12.6-point spread. Note the risk asymmetry: CBT runs 1.7 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
CBT vs MDY: side by side
| CBT (Cabot Corporation) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +5.7% | +18.3% |
| 5-year return | +73.1% | +47.5% |
| Volatility (ann.) | 28.5% | 16.5% |
| Beta vs S&P 500 | 0.84 | 0.91 |
| Max drawdown (3Y) | -48.8% | -24.0% |
| Market cap | $4.4B | – |
| P/E (trailing) | 23.7 | – |
| Dividend yield | 2.16% | 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 | CBT | MDY |
|---|---|---|
| 2022 | +21.4% | -13.3% |
| 2023 | +27.6% | +16.1% |
| 2024 | +11.3% | +13.6% |
| 2025 | -25.7% | +7.2% |
| 2026 | +29.1% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.12% of MDY is CBT itself, so the fund partly moves with the stock by construction.
Are CBT and MDY good diversifiers for each other?
Only partially. A correlation of 0.61 means CBT 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 CBT and MDY?
As of 2026-08-27, the correlation of weekly returns between CBT and MDY is 0.61 over 3 years, 0.53 over 1 year and 0.67 over 5 years.
Is MDY a good diversifier for CBT?
Only partially. A correlation of 0.61 means CBT 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 0.61 mean?
On the −1 to +1 scale, 0.61 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/cbt-vs-mdy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/cbt-vs-mdy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: CBT correlations · MDY correlations
