MD vs SPY: Correlation
Measured on weekly returns over the past three years, Pediatrix Medical Group, Inc. (MD) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.10, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MD and SPY?
On 3 years of weekly data the MD/SPY correlation comes out at 0.10, weak. The relationship has been stable: the 1-year correlation (0.05) sits close to the 3-year figure. The 5-year figure is 0.27, and annualized covariance runs at 68.0 %².
By 3-year correlation, SPY places #6 of the 11 assets tracked against MD. Their recent paths diverged sharply: over the last 12 months MD outperformed by 35.4 percentage points (+56.0% for MD against +20.6% for SPY). Note the risk asymmetry: MD runs 3.2 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.
MD vs SPY: side by side
| MD (Pediatrix Medical Group, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +56.0% | +20.6% |
| 5-year return | -23.8% | +82.4% |
| Volatility (ann.) | 46.2% | 14.5% |
| Beta vs S&P 500 | 0.33 | 1.00 |
| Max drawdown (3Y) | -52.8% | -18.8% |
| Market cap | $2.2B | – |
| P/E (trailing) | 12.9 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | ETF · US Large Cap |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | MD | SPY |
|---|---|---|
| 2022 | -45.4% | -18.2% |
| 2023 | -37.4% | +26.2% |
| 2024 | +41.1% | +24.9% |
| 2025 | +63.0% | +17.7% |
| 2026 | +25.3% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MD and SPY good diversifiers for each other?
By historical standards, yes. A correlation of 0.10 means the two rarely move for the same reasons.
FAQ
What is the correlation between MD and SPY?
Using weekly returns as of 2026-08-27: 0.10 over 3 years, with 0.05 over the last year and 0.27 over 5 years.
Is SPY a good diversifier for MD?
By historical standards, yes. A correlation of 0.10 means the two rarely move for the same reasons.
What does a correlation of 0.10 mean?
A reading of 0.10 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: MD correlations · SPY correlations
