CLB vs NPKI: Correlation
How closely do Core Laboratories Inc. (CLB) and NPK International Inc. (NPKI) trade together? Their weekly returns over three years give a correlation of 0.52, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CLB and NPKI?
Over the past 3 years, CLB and NPKI moved with a correlation of 0.52, which is moderate. The relationship has been stable: the 1-year correlation (0.51) sits close to the 3-year figure. Over 5 years the correlation is 0.60, and the annualized covariance of weekly returns is 1133.5 %².
Among the 15 assets we track against CLB, NPKI ranks #6 by 3-year correlation. The last year tells two different stories: NPKI led by 21.0 percentage points, +10.6% for CLB against +31.6% for NPKI.
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.
CLB vs NPKI: side by side
| CLB (Core Laboratories Inc.) | NPKI (NPK International Inc.) | |
|---|---|---|
| 1-year return | +10.6% | +31.6% |
| 5-year return | -55.8% | +429.3% |
| Volatility (ann.) | 53.1% | 41.0% |
| Beta vs S&P 500 | 0.91 | 0.88 |
| Max drawdown (3Y) | -62.5% | -42.1% |
| Market cap | $0.6B | $1.2B |
| P/E (trailing) | 23.2 | 28.8 |
| Dividend yield | 0.33% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | CLB | NPKI |
|---|---|---|
| 2022 | -9.0% | +41.2% |
| 2023 | -12.7% | +60.0% |
| 2024 | -1.8% | +15.5% |
| 2025 | -7.1% | +55.4% |
| 2026 | -23.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CLB and NPKI good diversifiers for each other?
To a limited degree. At 0.52 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 CLB and NPKI?
As of 2026-08-27, the correlation of weekly returns between CLB and NPKI is 0.52 over 3 years, 0.51 over 1 year and 0.60 over 5 years.
Is NPKI a good diversifier for CLB?
To a limited degree. At 0.52 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 0.52 mean?
On the −1 to +1 scale, 0.52 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/clb-vs-npki.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/clb-vs-npki/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: CLB correlations · NPKI correlations
