ARCT vs SPY: Correlation
Measured on weekly returns over the past three years, Arcturus Therapeutics Holdings Inc. (ARCT) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.38, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ARCT and SPY?
Across a 3-year window, the weekly returns of ARCT and SPY correlate at 0.38, moderate. The link has loosened recently: the 1-year correlation (0.25) runs below the 3-year figure (0.38). Stretching to 5 years gives 0.38, with an annualized covariance of 500.3 %².
Out of 14 assets tracked against ARCT, SPY lands near the bottom at #10. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 27.1 percentage points (-6.5% for ARCT against +20.6% for SPY). Note the risk asymmetry: ARCT runs 6.2 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.
ARCT vs SPY: side by side
| ARCT (Arcturus Therapeutics Holdings Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -6.5% | +20.6% |
| 5-year return | -69.9% | +82.4% |
| Volatility (ann.) | 90.6% | 14.5% |
| Beta vs S&P 500 | 2.39 | 1.00 |
| Max drawdown (3Y) | -87.5% | -18.8% |
| Market cap | $0.5B | – |
| 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 | ARCT | SPY |
|---|---|---|
| 2022 | -54.2% | -18.2% |
| 2023 | +85.9% | +26.2% |
| 2024 | -46.2% | +24.9% |
| 2025 | -63.9% | +17.7% |
| 2026 | +163.8% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ARCT and SPY good diversifiers for each other?
A fair diversifier. At 0.38, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between ARCT and SPY?
Using weekly returns as of 2026-08-27: 0.38 over 3 years, with 0.25 over the last year and 0.38 over 5 years.
Is SPY a good diversifier for ARCT?
A fair diversifier. At 0.38, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.38 mean?
A reading of 0.38 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: ARCT correlations · SPY correlations
