SPY vs XLO: Correlation
How closely do SPDR S&P 500 ETF Trust (SPY) and Xilio Therapeutics, Inc. (XLO) trade together? Their weekly returns over three years give a correlation of -0.01, which is near-zero.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and XLO?
Across a 3-year window, the weekly returns of SPY and XLO correlate at -0.01, near zero, meaning they move largely independently. Recent behaviour matches the longer record: 0.04 over 1 year against -0.01 over 3. Stretching to 5 years gives 0.15, with an annualized covariance of -14.7 %².
Within SPY's tracked universe of 4755 assets, XLO comes in at #4623 by 3-year correlation. The last year tells two different stories: SPY led by 26.6 percentage points, +20.6% for SPY against -6.0% for XLO. Note the risk asymmetry: XLO runs 6.6 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.
SPY vs XLO: side by side
| SPY (SPDR S&P 500 ETF Trust) | XLO (Xilio Therapeutics, Inc.) | |
|---|---|---|
| 1-year return | +20.6% | -6.0% |
| 5-year return | +82.4% | -96.0% |
| Volatility (ann.) | 14.5% | 96.4% |
| Beta vs S&P 500 | 1.00 | -0.07 |
| Max drawdown (3Y) | -18.8% | -82.8% |
| Market cap | – | $0.1B |
| P/E (trailing) | – | – |
| Dividend yield | 1.01% | 0.00% |
| Expense ratio | 0.09% | – |
| Assets under management | $795.3B | – |
| Sector / category | ETF · US Large Cap | US Listed |
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 | SPY | XLO |
|---|---|---|
| 2022 | -18.2% | -83.2% |
| 2023 | +26.2% | -79.6% |
| 2024 | +24.9% | +73.6% |
| 2025 | +17.7% | -33.0% |
| 2026 | +13.7% | +0.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and XLO good diversifiers for each other?
Yes. With a correlation of -0.01, SPY and XLO have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between SPY and XLO?
The SPY/XLO correlation stands at -0.01 on a 3-year window (1 year: 0.04, 5 years: 0.15), computed from weekly returns as of 2026-08-27.
Is XLO a good diversifier for SPY?
Yes. With a correlation of -0.01, SPY and XLO have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of -0.01 mean?
A reading of -0.01 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/spy-vs-xlo.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/spy-vs-xlo/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: SPY correlations · XLO correlations
