Merck & Co.vs.Pfizer
MRK vs PFE · both in Big pharma, part of the Medicine, pharma & life science value chain: Large, diversified pharmaceutical groups with broad portfolios across therapeutic areas.
Merck & Co. is about 2.2× larger than Pfizer by market cap; Pfizer trades at the lower P/E (36.3 vs 109.9); year to date, Merck & Co. leads (+35.7% vs +12.4%).
Side by side
| MRK | PFE | |
|---|---|---|
| Market cap | $349B | $157B |
| Price | $142.38 | $27.82 |
| Today | −0.3% | −0.6% |
| Return YTD | +35.7% | +12.4% |
| Return 1Y | +63.0% | +6.6% |
| Since June 26, 2026 | +10.7% | +14.5% |
| P/E | 109.9 | 36.3 |
| P/S | 5.2 | 2.5 |
| P/B | 8.3 | 1.8 |
Data as of 2026-10-08 · updates daily after U.S. close
Since June 26, 2026: the change in the closing price, from the daily closes Sectivia records itself since that date.
The two companies
Merck & Co.MRK
Keytruda is the centre of the oncology business, which sits next to a substantial vaccines portfolio. Animal health forms a third division.
Full MRK profile →PfizerPFE
Vaccines are what most people associate with Pfizer. The portfolio is considerably broader: oncology is a large part of it, and internal medicine covers much of the rest.
Full PFE profile →More MRK & PFE comparisons
Other head-to-heads in the Big pharma segment.