MRK vs VRTX: Correlation
Merck & Co. (MRK) and Vertex Pharmaceuticals (VRTX) show a moderate relationship: their 3-year correlation of weekly returns is 0.37.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MRK and VRTX?
Across a 3-year window, the weekly returns of MRK and VRTX correlate at 0.37, moderate. Recent behaviour matches the longer record: 0.43 over 1 year against 0.37 over 3. Stretching to 5 years gives 0.33, with an annualized covariance of 312.6 %².
Within MRK's tracked universe of 34 assets, VRTX comes in at #21 by 3-year correlation. Correlation aside, the last 12 months split them widely, with MRK ahead by 43.1 points (+83.8% versus +40.7%). On a rolling one-year basis the correlation drifted between 0.15 and 0.45, a moderate band.
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 VRTX: side by side
| MRK (Merck & Co.) | VRTX (Vertex Pharmaceuticals) | |
|---|---|---|
| 1-year return | +83.8% | +40.7% |
| 5-year return | +128.5% | +174.5% |
| Volatility (ann.) | 27.9% | 30.3% |
| Beta vs S&P 500 | 0.28 | 0.55 |
| Max drawdown (3Y) | -43.4% | -29.1% |
| Market cap | $368.9B | $138.8B |
| P/E (trailing) | 121.6 | 31.9 |
| Dividend yield | 2.17% | 0.00% |
| Sector / category | Health Care | Health Care |
Year-by-year returns
| Year | MRK | VRTX |
|---|---|---|
| 2022 | +49.4% | +31.5% |
| 2023 | +1.0% | +40.9% |
| 2024 | -6.3% | -1.0% |
| 2025 | +9.8% | +12.6% |
| 2026 | +44.1% | +20.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MRK and VRTX good diversifiers for each other?
Reasonably. At 0.37, MRK and VRTX keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between MRK and VRTX?
The MRK/VRTX correlation stands at 0.37 on a 3-year window (1 year: 0.43, 5 years: 0.33), computed from weekly returns as of 2026-08-27.
Is VRTX a good diversifier for MRK?
Reasonably. At 0.37, MRK and VRTX keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.37 mean?
A reading of 0.37 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/mrk-vs-vrtx.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mrk-vs-vrtx/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MRK correlations · VRTX correlations
