ICLR vs SPY: Correlation
Measured on weekly returns over the past three years, ICON plc (ICLR) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.29, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ICLR and SPY?
Across a 3-year window, the weekly returns of ICLR and SPY correlate at 0.29, weak. Recent behaviour matches the longer record: 0.23 over 1 year against 0.29 over 3. Stretching to 5 years gives 0.43, with an annualized covariance of 215.5 %².
SPY is close to the least connected end of ICLR's tracked universe, ranking #7 of 11. Correlation aside, the last 12 months split them widely, with SPY ahead by 23.1 points (-2.5% versus +20.6%). Note the risk asymmetry: ICLR runs 3.5 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.
ICLR vs SPY: side by side
| ICLR (ICON plc) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -2.5% | +20.6% |
| 5-year return | -33.7% | +82.4% |
| Volatility (ann.) | 51.4% | 14.5% |
| Beta vs S&P 500 | 1.03 | 1.00 |
| Max drawdown (3Y) | -76.9% | -18.8% |
| Market cap | $13.1B | – |
| P/E (trailing) | 265.2 | – |
| 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 | ICLR | SPY |
|---|---|---|
| 2022 | -37.3% | -18.2% |
| 2023 | +45.7% | +26.2% |
| 2024 | -25.9% | +24.9% |
| 2025 | -13.1% | +17.7% |
| 2026 | -6.9% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ICLR and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.29 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between ICLR and SPY?
Using weekly returns as of 2026-08-27: 0.29 over 3 years, with 0.23 over the last year and 0.43 over 5 years.
Is SPY a good diversifier for ICLR?
Yes, to a useful degree: a correlation of 0.29 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.29 mean?
A reading of 0.29 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: ICLR correlations · SPY correlations
