PFE vs MRK: Pfizer Inc. and Merck & Co. compared

Over the past five years, $10,000 in MRK grew to $23,876, against $8,211 in PFE. It also fell less at its worst: −41%, against −57%.

stock head-to-headdividends reinvesteddata through Sep 2026

growth of $10,000
as of Sep 2026PFE $8,211MRK $23,876

the gap between themMRK ahead by $15,665

PFE solid · MRK dashed · weekly closes, dividends reinvested

who comes out aheadPFE 2 · 2 MRK

Even at 2 each. The difference is in the details below.

  • Grew more over five yearsPFE −18% · MRK +139%Merck & Co. logoMRK
  • Fell less at its worstPFE −57% · MRK −41%Merck & Co. logoMRK
  • Calmer ridePFE 25% vol · MRK 26% volPfizer Inc. logoPFE
  • Pays more incomePFE 6.22% · MRK 2.31%Pfizer Inc. logoPFE

loosely linked · correlation 0.39

01The numbers

Side by side, line by line

head to head11 lines
PFE and MRK compared on price, size, returns, risk and cost
MetricPfizer Inc. logoPFEMerck & Co. logoMRK
Price$27.66$146.87
Market value$157.65B$362.35B
1-year return+23.2%+85.5% (ahead)
3-year return, a year−0.5%+14.4% (ahead)
5-year return, a year−3.9%+19.0% (ahead)
Volatility, a year25% (ahead)26%
Worst drawdown−57%−41% (ahead)
Worst week−9.5% (ahead)Oct 2025−11.7%Feb 2025
Beta0.300.23
P/E ratio36.4×117.5×
Dividend yield6.22%2.31%
marks the side ahead on lines with a direction: higher return, lower volatility, shallower fall, lower fee
02Together

Do PFE and MRK move together?

correlationloosely linked
0.39Loosely linked: they often part ways, so each can soften the other’s bad weeks.

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.

Pearson correlation of weekly returns|+1 always together, 0 unrelated, −1 always opposite
03Drawdowns

How far each one fell

drawdownsbelow each one’s previous high
as of Sep 2026PFE −39.9%MRK −3.2%

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

04Questions

PFE vs MRK: what people ask

questions5 answered

Is PFE better than MRK?

Over the past five years, MRK delivered the higher return: +19.0% 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.

Compare something else

Any two stocks or ETFs. Keep PFE or swap both.

Pfizer Inc. logo
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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.