RDNT vs SPY: Correlation
How closely do RadNet, Inc. (RDNT) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.44, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are RDNT and SPY?
On 3 years of weekly data the RDNT/SPY correlation comes out at 0.44, moderate. The relationship has been stable: the 1-year correlation (0.34) sits close to the 3-year figure. The 5-year figure is 0.45, and annualized covariance runs at 268.9 %².
By 3-year correlation, SPY places #6 of the 12 assets tracked against RDNT. On 12-month performance SPY holds a 14.9-point edge, +5.7% against +20.6%. One caveat on sizing: RDNT is 2.9 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.
RDNT vs SPY: side by side
| RDNT (RadNet, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +5.7% | +20.6% |
| 5-year return | +146.0% | +82.4% |
| Volatility (ann.) | 42.6% | 14.5% |
| Beta vs S&P 500 | 1.29 | 1.00 |
| Max drawdown (3Y) | -46.8% | -18.8% |
| Market cap | $5.9B | – |
| P/E (trailing) | – | – |
| 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 | RDNT | SPY |
|---|---|---|
| 2022 | -37.5% | -18.2% |
| 2023 | +84.7% | +26.2% |
| 2024 | +100.9% | +24.9% |
| 2025 | +2.2% | +17.7% |
| 2026 | +5.6% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are RDNT and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.44 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between RDNT and SPY?
Using weekly returns as of 2026-08-27: 0.44 over 3 years, with 0.34 over the last year and 0.45 over 5 years.
Is SPY a good diversifier for RDNT?
Yes, to a useful degree: a correlation of 0.44 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.44 mean?
A reading of 0.44 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: RDNT correlations · SPY correlations
