Merck vs Pfizer (MRK vs PFE)
Side by side from their SEC filings: revenue, margins, growth, returns and valuation, plus short interest, insider activity and institutional ownership.
Merck is the larger company by revenue ($65.0B vs $62.6B) and market value ($369.7B vs $162.7B). Merck has grown revenue faster over the last 4 fiscal years (+33.5% cumulative vs -23.0%). Pfizer trades at the lower trailing P/E (37.6x vs 118.0x).
About Merck
Merck & Co., Inc. is a pharmaceutical company that develops and sells prescription medicines, vaccines, and animal health products. It serves healthcare providers, patients, and animal health customers worldwide. The company also collaborates with other firms to develop and commercialize various pharmaceutical products.
About Pfizer
Pfizer Inc. is a global biopharmaceutical company that discovers, develops, manufactures, markets, sells, and distributes medicines and vaccines worldwide. Its main products include treatments in oncology, internal medicine, vaccines, inflammation, and immunology, serving healthcare providers and patients across developed and emerging markets. Pfizer operates through its Biopharma segment, which manages commercial operations and product portfolios such as primary care, specialty care, oncology, and hospital and biosimilars.
Head to head (MRK FY2025 vs PFE FY2025)
| Metric | MRKFY2025 | PFEFY2025 |
|---|---|---|
| Revenue | $65.01B | $62.58B |
| Revenue growth (YoY) | 1.3% | -1.6% |
| Gross margin | 74.8% | 74.3% |
| Operating margin | — | — |
| Net margin | 28.1% | 12.4% |
| Net income | $18.25B | $7.77B |
| Diluted EPS | $7.28 | $1.36 |
| FCF margin | 19.0% | 14.5% |
| ROE | 34.7% | 9.0% |
| Long-term debt / equity | 0.89× | 0.71× |
| Market cap | $369.73B | $162.73B |
| P/E | 118.0× | 37.6× |
Fundamentals are from each company’s SEC filings (MRK FY2025, PFE FY2025). ROE is net income over fiscal-year-end equity; long-term debt / equity counts non-current term debt only. P/E and market cap are derived from stored market prices, last retrieved on a rolling basis and typically within the past week.
Five-year trend (as reported)
| Revenue | FY2021 | FY2022 | FY2023 | FY2024 | FY2025 |
|---|---|---|---|---|---|
| MRK | $48.70B | $59.28B | $60.12B | $64.17B | $65.01B |
| PFE | $81.29B | $91.79B | $59.55B | $63.63B | $62.58B |
Peer standing
Where each company ranks among the 198 pharmaceutical companies, on the same scale. Each figure is ranked only against peers that report it. Percentiles describe position in the distribution, not a rating.
| Metric | MRK | PFE |
|---|---|---|
| Gross margin | 74.8%68th percentile of 69 | 74.3%65th percentile of 69 |
| Net margin | 28.1%82nd percentile of 122 | 12.4%72nd percentile of 122 |
| FCF margin | 19.0%77th percentile of 110 | 14.5%67th percentile of 110 |
| Revenue growth (YoY) | +1.3%36th percentile of 187 | -1.6%31st percentile of 187 |
| ROE | 34.7%91st percentile of 167 | 9.0%73rd percentile of 167 |
| P/E | 118.0×90th percentile of 60 | 37.6×76th percentile of 60 |
| Long-term debt / equity | 0.89×78th percentile of 64 | 0.71×60th percentile of 64 |
| Short interest (days to cover) | 2.84d23rd percentile of 197 | 3.53d30th percentile of 197 |
Short interest
| FINRA settlement data | MRK | PFE |
|---|---|---|
| Shares sold short | 24.5M | 149.3M |
| Change vs prior settlement | -13.4% | -7.6% |
| Days to cover | 2.84 | 3.53 |
| As of settlement | 2026-08-14 | 2026-08-14 |
Source: FINRA Consolidated Short Interest. FINRA is the owner and source of the FINRA-supplied data; republishing or redistributing it is not permitted. Not presented as a percentage of float. No FINRA endorsement of this product is implied.
Insider activity (last 90 days)
| Form 4 activity (codes P/S) | MRK | PFE |
|---|---|---|
| Buys | 0 | 3 ($3.0M) |
| Sells | 17 ($30.0M) | 2 ($134,661) |
Non-derivative purchases (code P) and sales (code S) reported on SEC Form 4, which may be open-market or private (grants, exercises and tax withholding excluded). For context, about 15% of covered companies saw any reported insider purchase (code P) in a 90-day window.
Held by the same investors
8 tracked 13F managers hold both Merck and Pfizer as of their latest quarterly filings: AQR Capital Management, Bridgewater Associates, Citadel Advisors, D. E. Shaw, Dodge & Cox, Gotham Asset Management, Millennium Management, Two Sigma Investments. See which superinvestors hold your own portfolio with the smart money checker.
Go deeper
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Data sourced from SEC EDGAR. Figures are as-reported and may be unaudited or restated; verify against the source filings before relying on them. Comparisons are descriptive (higher or lower on a reported figure), not a rating or a recommendation. Informational only. Not investment advice.