CIEN vs XLK: Correlation
Ciena (CIEN) and Technology Select Sector SPDR Fund (XLK) show a moderate relationship: their 3-year correlation of weekly returns is 0.47.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CIEN and XLK?
Across a 3-year window, the weekly returns of CIEN and XLK correlate at 0.47, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.28 versus 0.47 over 3 years. Stretching to 5 years gives 0.51, with an annualized covariance of 561.8 %².
By 3-year correlation, XLK places #17 of the 28 assets tracked against CIEN. Correlation aside, the last 12 months split them widely, with CIEN ahead by 287.8 points (+331.2% versus +43.4%). Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from 0.17 to 0.70. Note the risk asymmetry: CIEN runs 2.1 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 XLK: side by side
| CIEN (Ciena) | XLK (Technology Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | +331.2% | +43.4% |
| 5-year return | +598.5% | +145.2% |
| Volatility (ann.) | 50.1% | 24.0% |
| Beta vs S&P 500 | 1.59 | 1.50 |
| Max drawdown (3Y) | -47.3% | -25.7% |
| Market cap | $56.6B | – |
| P/E (trailing) | 133.7 | – |
| Dividend yield | 0.00% | 0.45% |
| Expense ratio | – | 0.08% |
| Assets under management | – | $115.4B |
| Sector / category | Information Technology | Sector ETF |
On the fund side, XLK sits in the Technology category at State Street Investment Management, with $115.4B under management, 73 holdings, a 0.08% expense ratio, a 0.45% trailing dividend yield.
Year-by-year returns
| Year | CIEN | XLK |
|---|---|---|
| 2022 | -33.8% | -27.7% |
| 2023 | -11.7% | +56.0% |
| 2024 | +88.4% | +21.6% |
| 2025 | +175.8% | +24.6% |
| 2026 | +71.0% | +31.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that XLK holds CIEN at a 0.38% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are CIEN and XLK good diversifiers for each other?
Reasonably. At 0.47, CIEN and XLK keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between CIEN and XLK?
As of 2026-08-27, the correlation of weekly returns between CIEN and XLK is 0.47 over 3 years, 0.28 over 1 year and 0.51 over 5 years.
Is XLK a good diversifier for CIEN?
Reasonably. At 0.47, CIEN and XLK keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.47 mean?
A reading of 0.47 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/cien-vs-xlk.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/cien-vs-xlk/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: CIEN correlations · XLK correlations
