What five years of weekly data say
- PFE returned −3.9% a year and MRK +18.4% a year over the past five years, dividends reinvested.
- PFE was the calmer ride: 25% annual volatility, against 26%.
- Loosely linked (correlation 0.39). They often part ways, so each can soften the other’s bad weeks.
- PFE pays more income: a 6.22% yield, against 2.31% for MRK.
The numbers side by side
| Metric | PFPFE | MRMRK |
|---|---|---|
| Price | $27.66 | $146.87 |
| Market value | $157.65B | $362.35B |
| 1-year return | +23.2% | +85.5% (ahead) |
| 3-year return, a year | +0.9% | +14.8% (ahead) |
| 5-year return, a year | −3.9% | +18.4% (ahead) |
| Volatility, a year | 25% (ahead) | 26% |
| Worst drawdown | −57% | −41% (ahead) |
| Worst week | −9.5% (ahead)Oct 2025 | −11.7%Feb 2025 |
| Beta | 0.30 | 0.23 |
| P/E ratio | 36.4× | 117.5× |
| Dividend yield | 6.22% | 2.31% |
Do PFE and MRK move together?
Correlation compares PFE’s and MRK’s weekly returns from Sep 2021 to Sep 2026. Two holdings near +1 fall on the same weeks, so owning both doesn’t cushion anything. Your portfolio has more than two lines, and Portfolio Terminal runs this check across every pair you hold.
How far each one fell
PFE
−57%
From its Dec 2021 high to Apr 2025. Still 40% below it today.
MRK
−41%
From its Mar 2024 high to May 2025. Back at that high by Jun 2026.
Worst peak-to-trough fall on weekly closes · dividends reinvested
PFE vs MRK: what people ask
Is PFE better than MRK?
Over the past five years, MRK delivered the higher return: +18.4% a year against −3.9% for PFE, dividends reinvested. Its worst fall was also shallower (−41% against −57%). Which is better depends on the job it does in your portfolio, and past returns don’t predict future ones.
What is the difference between PFE and MRK?
PFE is Pfizer Inc. (Drug Manufacturers—General), worth $157.65B. MRK is Merck & Co. (Drug Manufacturers—General), worth $362.35B.
Should I own both PFE and MRK?
Their weekly returns had a correlation of 0.39 over the past five years. They often part ways, so each can soften the other’s bad weeks. Whether that suits you depends on everything else you hold, which is the check Portfolio Terminal runs across a whole portfolio.
Which is riskier, PFE or MRK?
MRK swung more: 26% annual volatility against 25% for PFE. At their worst, PFE fell 57% and MRK 41% from a previous high. Against the broad market, their betas are 0.30 and 0.23.
Which pays a higher dividend, PFE or MRK?
PFE currently yields 6.22%, against 2.31% for MRK. Yields move with price, so a higher yield can also mean a falling price.
Returns use weekly closes adjusted for dividends and splits, from Sep 2021 to Sep 2026. Quotes, fees and holdings come from public market data and refresh hourly. This page describes what happened; it is not investment advice, and past performance doesn’t predict future returns.