COHR vs XLK: Correlation
How closely do Coherent Corp. (COHR) and Technology Select Sector SPDR Fund (XLK) trade together? Their weekly returns over three years give a correlation of 0.63, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are COHR and XLK?
On 3 years of weekly data the COHR/XLK correlation comes out at 0.63, strong. The link has loosened recently: the 1-year correlation (0.40) runs below the 3-year figure (0.63). The 5-year figure is 0.61, and annualized covariance runs at 989.9 %².
Among the 41 assets we track against COHR, XLK ranks #7 by 3-year correlation. Correlation aside, the last 12 months split them widely, with COHR ahead by 182.2 points (+225.6% versus +43.4%). The relationship is regime-dependent: the rolling one-year correlation swung between 0.24 and 0.84 over the past three years, so this pair behaves very differently depending on the market environment. One caveat on sizing: COHR is 2.7 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.
COHR vs XLK: side by side
| COHR (Coherent Corp.) | XLK (Technology Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | +225.6% | +43.4% |
| 5-year return | +368.6% | +145.2% |
| Volatility (ann.) | 65.0% | 24.0% |
| Beta vs S&P 500 | 2.76 | 1.50 |
| Max drawdown (3Y) | -54.8% | -25.7% |
| Market cap | $57.8B | – |
| P/E (trailing) | 71.4 | – |
| 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 | COHR | XLK |
|---|---|---|
| 2022 | -48.6% | -27.7% |
| 2023 | +24.0% | +56.0% |
| 2024 | +117.6% | +21.6% |
| 2025 | +94.8% | +24.6% |
| 2026 | +60.0% | +31.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.39% of XLK is COHR itself, so the fund partly moves with the stock by construction.
Are COHR and XLK good diversifiers for each other?
Only partially. A correlation of 0.63 means COHR and XLK share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between COHR and XLK?
The COHR/XLK correlation stands at 0.63 on a 3-year window (1 year: 0.40, 5 years: 0.61), computed from weekly returns as of 2026-08-27.
Is XLK a good diversifier for COHR?
Only partially. A correlation of 0.63 means COHR and XLK share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.63 mean?
On the −1 to +1 scale, 0.63 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/cohr-vs-xlk.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/cohr-vs-xlk/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: COHR correlations · XLK correlations
