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 (35.2 vs 103.9); year to date, Merck & Co. leads (+43.1% vs +12.3%).
Side by side
| MRK | PFE | |
|---|---|---|
| Market cap | $330B | $152B |
| Price | $156.45 | $28.57 |
| Today | +3.8% | +2.1% |
| Return YTD | +43.1% | +12.3% |
| Return 1Y | +72.4% | +8.1% |
| P/E | 103.9 | 35.2 |
| P/S | 5.0 | 2.4 |
| P/B | 7.2 | 1.8 |
Data as of 2026-08-26 · updates daily after U.S. close
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.
See where MRK and PFE sit in the full Medicine, pharma & life science map: every segment from suppliers to end markets.Open the Life science value chain →