ATRA vs SPY: Correlation
Measured on weekly returns over the past three years, Atara Biotherapeutics, Inc. (ATRA) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.11, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ATRA and SPY?
Across a 3-year window, the weekly returns of ATRA and SPY correlate at 0.11, weak. Recent behaviour matches the longer record: 0.18 over 1 year against 0.11 over 3. Stretching to 5 years gives 0.20, with an annualized covariance of 244.7 %².
Among the 13 assets we track against ATRA, SPY ranks #6 by 3-year correlation. Correlation aside, the last 12 months split them widely, with SPY ahead by 45.7 points (-25.1% versus +20.6%). Risk is not evenly split, since ATRA carries 10.6 times the volatility of the other side.
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.
ATRA vs SPY: side by side
| ATRA (Atara Biotherapeutics, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -25.1% | +20.6% |
| 5-year return | -97.5% | +82.4% |
| Volatility (ann.) | 153.2% | 14.5% |
| Beta vs S&P 500 | 1.17 | 1.00 |
| Max drawdown (3Y) | -90.7% | -18.8% |
| Market cap | $0.1B | – |
| 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 | ATRA | SPY |
|---|---|---|
| 2022 | -79.2% | -18.2% |
| 2023 | -84.4% | +26.2% |
| 2024 | +3.8% | +24.9% |
| 2025 | +35.9% | +17.7% |
| 2026 | -48.9% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ATRA and SPY good diversifiers for each other?
Yes. With a correlation of 0.11, ATRA and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between ATRA and SPY?
Using weekly returns as of 2026-08-27: 0.11 over 3 years, with 0.18 over the last year and 0.20 over 5 years.
Is SPY a good diversifier for ATRA?
Yes. With a correlation of 0.11, ATRA and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of 0.11 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
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Related comparisons
Hubs: ATRA correlations · SPY correlations
