CIEN vs CLS: Correlation
How closely do Ciena (CIEN) and Celestica, Inc. (CLS) trade together? Their weekly returns over three years give a correlation of 0.54, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CIEN and CLS?
Over the past 3 years, CIEN and CLS moved with a correlation of 0.54, which is moderate. Recent behaviour matches the longer record: 0.50 over 1 year against 0.54 over 3. Over 5 years the correlation is 0.50, and the annualized covariance of weekly returns is 1625.6 %².
CLS is one of the assets that tracks CIEN most closely: it ranks #3 out of the 28 assets we track against CIEN. The last year tells two different stories: CIEN led by 274.2 percentage points, +331.2% for CIEN against +57.0% for CLS.
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 CLS: side by side
| CIEN (Ciena) | CLS (Celestica, Inc.) | |
|---|---|---|
| 1-year return | +331.2% | +57.0% |
| 5-year return | +598.5% | +3251.4% |
| Volatility (ann.) | 50.1% | 60.6% |
| Beta vs S&P 500 | 1.59 | 2.49 |
| Max drawdown (3Y) | -47.3% | -54.0% |
| Market cap | $56.6B | $40.0B |
| P/E (trailing) | 133.7 | 32.0 |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | Information Technology | US Listed |
Year-by-year returns
| Year | CIEN | CLS |
|---|---|---|
| 2022 | -33.8% | +1.3% |
| 2023 | -11.7% | +159.8% |
| 2024 | +88.4% | +215.2% |
| 2025 | +175.8% | +220.3% |
| 2026 | +71.0% | +7.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CIEN and CLS good diversifiers for each other?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between CIEN and CLS?
Using weekly returns as of 2026-08-27: 0.54 over 3 years, with 0.50 over the last year and 0.50 over 5 years.
Is CLS a good diversifier for CIEN?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.54 mean?
On the −1 to +1 scale, 0.54 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/cien-vs-cls.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/cien-vs-cls/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: CIEN correlations · CLS correlations
