MRK vs TMO: Correlation
Merck & Co. (MRK) and Thermo Fisher Scientific (TMO) show a moderate relationship: their 3-year correlation of weekly returns is 0.48.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MRK and TMO?
Over the past 3 years, MRK and TMO moved with a correlation of 0.48, which is moderate. Little has changed lately, as the 1-year reading of 0.47 lands near the 3-year figure. Over 5 years the correlation is 0.35, and the annualized covariance of weekly returns is 392.7 %².
By 3-year correlation, TMO places #13 of the 34 assets tracked against MRK. The last year tells two different stories: MRK led by 54.1 percentage points, +83.8% for MRK against +29.7% for TMO. The relationship is regime-dependent: the rolling one-year correlation swung between -0.12 and 0.74 over the past three years, so this pair behaves very differently depending on the market environment.
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.
MRK vs TMO: side by side
| MRK (Merck & Co.) | TMO (Thermo Fisher Scientific) | |
|---|---|---|
| 1-year return | +83.8% | +29.7% |
| 5-year return | +128.5% | +14.5% |
| Volatility (ann.) | 27.9% | 29.4% |
| Beta vs S&P 500 | 0.28 | 0.74 |
| Max drawdown (3Y) | -43.4% | -37.3% |
| Market cap | $368.9B | $233.2B |
| P/E (trailing) | 121.6 | 34.1 |
| Dividend yield | 2.17% | 0.28% |
| Sector / category | Health Care | Health Care |
Year-by-year returns
| Year | MRK | TMO |
|---|---|---|
| 2022 | +49.4% | -17.3% |
| 2023 | +1.0% | -3.4% |
| 2024 | -6.3% | -1.7% |
| 2025 | +9.8% | +11.8% |
| 2026 | +44.1% | +9.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MRK and TMO good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.48 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between MRK and TMO?
The MRK/TMO correlation stands at 0.48 on a 3-year window (1 year: 0.47, 5 years: 0.35), computed from weekly returns as of 2026-08-27.
Is TMO a good diversifier for MRK?
Yes, to a useful degree: a correlation of 0.48 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.48 mean?
On the −1 to +1 scale, 0.48 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/mrk-vs-tmo.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/mrk-vs-tmo/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MRK correlations · TMO correlations
