MDY vs SWK: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and Stanley Black & Decker (SWK) trade together? Their weekly returns over three years give a correlation of 0.69, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and SWK?
Over the past 3 years, MDY and SWK moved with a correlation of 0.69, which is strong. Lately the two have moved closer together, with the 1-year correlation at 0.80 versus 0.69 over 3 years. Over 5 years the correlation is 0.67, and the annualized covariance of weekly returns is 401.1 %².
By 3-year correlation, SWK places #72 of the 359 assets tracked against MDY. Correlation aside, the last 12 months split them widely, with SWK ahead by 18.7 points (+18.3% versus +37.0%). Across three years, the rolling one-year figure varied moderately, from 0.49 to 0.86. One caveat on sizing: SWK is 2.1 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 SWK: side by side
| MDY (SPDR S&P MidCap 400 ETF) | SWK (Stanley Black & Decker) | |
|---|---|---|
| 1-year return | +18.3% | +37.0% |
| 5-year return | +47.5% | -39.1% |
| Volatility (ann.) | 16.5% | 35.4% |
| Beta vs S&P 500 | 0.91 | 1.19 |
| Max drawdown (3Y) | -24.0% | -48.3% |
| Market cap | – | $15.0B |
| P/E (trailing) | – | 24.4 |
| Dividend yield | 1.02% | 3.33% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | Industrials |
On the fund side, MDY sits in the Mid-Cap Blend category at State Street Investment Management, with $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | SWK |
|---|---|---|
| 2022 | -13.3% | -58.9% |
| 2023 | +16.1% | +35.6% |
| 2024 | +13.6% | -15.2% |
| 2025 | +7.2% | -3.2% |
| 2026 | +16.4% | +36.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and SWK good diversifiers for each other?
Only partially. A correlation of 0.69 means MDY and SWK 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 SWK?
The MDY/SWK correlation stands at 0.69 on a 3-year window (1 year: 0.80, 5 years: 0.67), computed from weekly returns as of 2026-08-27.
Is SWK a good diversifier for MDY?
Only partially. A correlation of 0.69 means MDY and SWK share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.69 mean?
A reading of 0.69 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-swk.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-swk/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · SWK correlations
