ACFN vs SPY: Correlation
How closely do Acorn Energy, Inc. (ACFN) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.12, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ACFN and SPY?
Across a 3-year window, the weekly returns of ACFN and SPY correlate at 0.12, weak. Recent behaviour matches the longer record: 0.21 over 1 year against 0.12 over 3. Stretching to 5 years gives 0.01, with an annualized covariance of 141.1 %².
Among the 14 assets we track against ACFN, SPY ranks #8 by 3-year correlation. Correlation aside, the last 12 months split them widely, with SPY ahead by 47.6 points (-27.0% versus +20.6%). Risk is not evenly split, since ACFN carries 5.6 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.
ACFN vs SPY: side by side
| ACFN (Acorn Energy, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -27.0% | +20.6% |
| 5-year return | +122.5% | +82.4% |
| Volatility (ann.) | 81.3% | 14.5% |
| Beta vs S&P 500 | 0.68 | 1.00 |
| Max drawdown (3Y) | -58.1% | -18.8% |
| Market cap | $0.1B | – |
| P/E (trailing) | 33.9 | – |
| 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 | ACFN | SPY |
|---|---|---|
| 2022 | -44.4% | -18.2% |
| 2023 | +8.8% | +26.2% |
| 2024 | +193.8% | +24.9% |
| 2025 | -15.6% | +17.7% |
| 2026 | +36.8% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ACFN and SPY good diversifiers for each other?
Yes: at 0.12, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between ACFN and SPY?
As of 2026-08-27, the correlation of weekly returns between ACFN and SPY is 0.12 over 3 years, 0.21 over 1 year and 0.01 over 5 years.
Is SPY a good diversifier for ACFN?
Yes: at 0.12, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of 0.12 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: ACFN correlations · SPY correlations
