CIEN vs SPY: Correlation
How closely do Ciena (CIEN) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.46, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CIEN and SPY?
Over the past 3 years, CIEN and SPY moved with a correlation of 0.46, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.25 versus 0.46 over 3 years. Over 5 years the correlation is 0.49, and the annualized covariance of weekly returns is 332.2 %².
Among the 28 assets we track against CIEN, SPY ranks #18 by 3-year correlation. Correlation aside, the last 12 months split them widely, with CIEN ahead by 310.6 points (+331.2% versus +20.6%). The relationship is regime-dependent: the rolling one-year correlation swung between 0.18 and 0.70 over the past three years, so this pair behaves very differently depending on the market environment. Note the risk asymmetry: CIEN runs 3.5 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.
CIEN vs SPY: side by side
| CIEN (Ciena) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +331.2% | +20.6% |
| 5-year return | +598.5% | +82.4% |
| Volatility (ann.) | 50.1% | 14.5% |
| Beta vs S&P 500 | 1.59 | 1.00 |
| Max drawdown (3Y) | -47.3% | -18.8% |
| Market cap | $56.6B | – |
| P/E (trailing) | 133.7 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Information Technology | 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 | CIEN | SPY |
|---|---|---|
| 2022 | -33.8% | -18.2% |
| 2023 | -11.7% | +26.2% |
| 2024 | +88.4% | +24.9% |
| 2025 | +175.8% | +17.7% |
| 2026 | +71.0% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
CIEN represents 0.09% of SPY's portfolio, so part of any move in SPY is CIEN itself, and the correlation between them is partly mechanical.
Are CIEN and SPY good diversifiers for each other?
A fair diversifier. At 0.46, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between CIEN and SPY?
Using weekly returns as of 2026-08-27: 0.46 over 3 years, with 0.25 over the last year and 0.49 over 5 years.
Is SPY a good diversifier for CIEN?
A fair diversifier. At 0.46, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.46 mean?
A reading of 0.46 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: CIEN correlations · SPY correlations
