MDY vs ONEW: Correlation
Measured on weekly returns over the past three years, SPDR S&P MidCap 400 ETF (MDY) and OneWater Marine Inc. (ONEW) carry a correlation of 0.60, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and ONEW?
On 3 years of weekly data the MDY/ONEW correlation comes out at 0.60, strong. The relationship has been stable: the 1-year correlation (0.62) sits close to the 3-year figure. The 5-year figure is 0.54, and annualized covariance runs at 581.1 %².
Within MDY's tracked universe of 359 assets, ONEW comes in at #180 by 3-year correlation. Correlation aside, the last 12 months split them widely, with MDY ahead by 51.5 points (+18.3% versus -33.2%). One caveat on sizing: ONEW is 3.6 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.
MDY vs ONEW: side by side
| MDY (SPDR S&P MidCap 400 ETF) | ONEW (OneWater Marine Inc.) | |
|---|---|---|
| 1-year return | +18.3% | -33.2% |
| 5-year return | +47.5% | -71.6% |
| Volatility (ann.) | 16.5% | 59.0% |
| Beta vs S&P 500 | 0.91 | 1.72 |
| Max drawdown (3Y) | -24.0% | -76.1% |
| Market cap | – | $0.2B |
| P/E (trailing) | – | – |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
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 | MDY | ONEW |
|---|---|---|
| 2022 | -13.3% | -53.1% |
| 2023 | +16.1% | +18.1% |
| 2024 | +13.6% | -48.6% |
| 2025 | +7.2% | -37.7% |
| 2026 | +16.4% | +7.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and ONEW good diversifiers for each other?
Only partially. A correlation of 0.60 means MDY and ONEW 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 MDY and ONEW?
Using weekly returns as of 2026-08-27: 0.60 over 3 years, with 0.62 over the last year and 0.54 over 5 years.
Is ONEW a good diversifier for MDY?
Only partially. A correlation of 0.60 means MDY and ONEW share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.60 mean?
On the −1 to +1 scale, 0.60 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/mdy-vs-onew.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-onew/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · ONEW correlations
