CISS vs SPY: Correlation
C3is Inc. (CISS) and SPDR S&P 500 ETF Trust (SPY) show a near-zero relationship: their 3-year correlation of weekly returns is 0.02.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CISS and SPY?
Over the past 3 years, CISS and SPY moved with a correlation of 0.02, which is near zero, meaning they move largely independently. Recent behaviour matches the longer record: 0.02 over 1 year against 0.02 over 3. Over 5 years the correlation is n/a, and the annualized covariance of weekly returns is 467.0 %².
Among the 42 assets we track against CISS, SPY ranks #19 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 120.1 percentage points (-99.5% for CISS against +20.6% for SPY). One caveat on sizing: CISS is 144.7 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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.
CISS vs SPY: side by side
| CISS (C3is Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -99.5% | +20.6% |
| 5-year return | n/a | +82.4% |
| Volatility (ann.) | 2098.5% | 14.5% |
| Beta vs S&P 500 | 2.24 | 1.00 |
| Max drawdown (3Y) | -100.0% | -18.8% |
| Market cap | – | – |
| 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 | CISS | SPY |
|---|---|---|
| 2022 | – | -18.2% |
| 2023 | – | +26.2% |
| 2024 | -98.9% | +24.9% |
| 2025 | -97.3% | +17.7% |
| 2026 | -93.4% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CISS and SPY good diversifiers for each other?
Yes: at 0.02, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between CISS and SPY?
The CISS/SPY correlation stands at 0.02 on a 3-year window (1 year: 0.02, 5 years: n/a), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for CISS?
Yes: at 0.02, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of 0.02 mean?
A reading of 0.02 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: CISS correlations · SPY correlations
