Sifting through countless of stocks in the Pharmaceuticals industry can be tedious, and sometimes two stocks are just too similar to judge which is the better investment. If you’re on the fence about investing in Pfizer Inc., Merck & Co. or Inc. because you’re not sure how they measure up, it’s important to compare them on a few factors before making your decision.

Read on to learn how Pfizer Inc., Merck & Co. and Inc. compare based on key financial metrics to determine which better meets your investment needs.

About Pfizer Inc., Merck & Co. and Inc.

Pfizer Inc. discovers, develops, manufactures, markets, distributes, and sells biopharmaceutical products in the United States and internationally. It operates in three segments: Biopharma, PC1, and Pfizer Ignite. The company offers internal medicine products, including cardiovascular metabolic diseases products under the Eliquis brand; migraine products under the Nurtec ODT/Vydura and Zavzpret brand; vaccines under the Prevnar family, Abrysvo, Nimenrix, FSME/IMMUN-TicoVac, and Trumenba brands; and Paxlovid for the treatment of COVID-19. It also provides inflammation and immunology products, such as Xeljanz, Enbrel, Cibinqo, Litfulo, Eucrisa, and Velsipity; rare disease products for therapeutic areas comprising amyloidosis, hemophilia, and endocrine diseases under the Vyndaqel family, Genotropin, BeneFIX, Xyntha, Somavert, Ngenla, and Hympavzi brands; and anti-infective and immunoglobulin medicines under the Zavicefta, Octagam, and Panzyga brands. In addition, the company offers oncology products comprising ADCs, small molecules, bispecific, and other immunotherapies for the treatment of cancers, including breast cancer, genitourinary cancer, and hematologic malignancies, as well as melanoma, gastrointestinal, gynecological, and lung cancer under the Ibrance, Xtandi, Padcev, Adcetris, Inlyta, Lorbrena, Bosulif, Tukysa, Braftovi, Mektovi, Orgovyx, Elrexfio, Tivdak, and Talzenna brands. Further, it provides biosimilars under the Inflectra brand; oncology biosimilars comprising Retacrit, Ruxience, Zirabev, Trazimera and Nivestym, and other biosimilars; and sterile injectables, such as Sulperazon, Atgam, Fragmin, Solu Medrol, Solu Cortef, and Bicillin. The company has collaboration agreements with Bristol-Myers Squibb Company; Astellas Pharma US, Inc.; Merck KGaA; and BioNTech SE, as well as a strategic collaboration with Boltz, PBC to develop and deploy biomolecular AI foundation models. Pfizer Inc. was founded in 1849 and is headquartered in New York, New York.

Merck & Co., Inc. operates as a healthcare company worldwide. It offers human health pharmaceutical for various areas under the Keytruda, Keytruda Qlex, Welireg, Gardasil, ProQuad, M-M-R II, Varivax, Vaxneuvance, Capvaxive, RotaTeq, Pneumovax 23, Bridion, Prevymis, Dificid, Zerbaxa, Winrevair, Adempas/ Verquvo, Ohtuvayre, Lagevrio, Isentress/Isentress HD, Delstrigo, Pifeltro, Belsomra, Januvia, and Janumet brands. The company also provides veterinary pharmaceuticals, vaccines and health management solutions and services, such as livestock products under the Nuflor, Bovilis/Vista, Bovilis Cryptium, Banamine, Estrumate, Matrix, Resflor, Zuprevo, Revalor, Safe-Guard, M+Pac, Porcilis, Circumvent, Nobilis/Innovax, Paracox and Coccivac, Exzolt, Slice, Imvixa, Clynav, Aquavac/Norvax, Aquaflor, Flexolt brands; Allflex Livestock Intelligence solutions; and companion animal products under the Bravecto One-Month, Bravecto Injectable/Quantum, Bravecto TriUNO, Bravecto Plus, Sentinel Spectrum, Sentinel Flavor Tabs, Numelvi, Optimmune, Nobivac NXT, GilvetMab, Otomax, Mometamax, Mometamax Ultra, Posatex, Caninsulin/Vetsulin, Panacur, Safeguard, Regumate, Prestige, Scalibor/Exspot, Sure Petcare, and Home Again brands. It has development and commercialization agreement for three of Daiichi Sankyo’s deruxtecan ADC candidates; AstraZeneca PLC to co-development and co-commercialize AstraZeneca’s Lynparza products for multiple cancer types; licensed to develop, manufacture and commercialize LM-299, a novel investigational PD-1/VEGF bispecific antibody from LaNova; and collaboration agreement with Eisai Co., Ltd., Bayer AG, and Ridgeback Biotherapeutics LP, as well Moderna, Inc. Merck & Co., Inc. has strategic collaboration with Infinimmune, Inc. to discover and develop antibodies against multiple therapeutic targets. The company was founded in 1891 and is headquartered in Rahway, New Jersey.

Latest Pharmaceuticals and Pfizer Inc., Merck & Co., Inc. Stock News

As of April 30, 2026, Pfizer Inc. had a $151.9 billion market capitalization, compared to the Pharmaceuticals median of $562.0 million. Pfizer Inc.’s stock is up 6.3% in 2026, down 2% in the previous five trading days and up 12.23% in the past year.

Currently, Pfizer Inc.’s price-earnings ratio is 19.6. Pfizer Inc.’s trailing 12-month revenue is $62.6 billion with a 12.4% net profit margin. Year-over-year quarterly sales growth most recently was -1.2%. Analysts expect adjusted earnings to reach $2.964 per share for the current fiscal year. Pfizer Inc. currently has a 6.4% dividend yield.

As of April 30, 2026, Merck & Co., Inc. had a $269.7 billion market cap, putting it in the 99th percentile of all stocks. Merck & Co., Inc.’s stock is up 8.3% in 2026, up 1.8% in the previous five trading days and up 28.89% in the past year.

Currently, Merck & Co., Inc.’s price-earnings ratio is 15.0. Merck & Co., Inc.’s trailing 12-month revenue is $65.0 billion with a 13.6% net profit margin. Year-over-year quarterly sales growth most recently was 5.0%. Analysts expect adjusted earnings to reach $5.106 per share for the current fiscal year. Merck & Co., Inc. currently has a 3.1% dividend yield.

How We Compare Pfizer Inc., Merck & Co. and Inc. Stock Grades

Stock evaluation requires access to huge amounts of data and the knowledge and time to sift through it all, make sense of financial ratios, read income statements and analyze recent stock movements. AAII created A+ Investor, a robust data suite that condenses data research in an actionable and customizable way suitable for investors of all knowledge levels, to help investors streamline and work through such data.

AAII’s proprietary stock grades come with A+ Investor. These offer intuitive A‐F grades for each of five key investing factors: value, growth, momentum, earnings estimate revisions and quality. Here, we’ll take a closer look at Pfizer Inc., Merck & Co. and Inc.’s stock grades to see how they measure up against one another.

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Pfizer Inc., Merck & Co. and Inc. Stock Value Grades

Company	Ticker	Value
Pfizer Inc.	PFE	B
Merck & Co., Inc.	MRK	D

Successful stock investing involves buying low and selling high, so stock valuation is an important consideration for stock selection.

Buying stocks that are going to go up typically means buying stocks that are undervalued in the first place, although momentum investors may argue that point.

AAII’s A+ Investor Value Grade derives from a stock’s value score. The Value Score is the percentile rank of the average of the percentile ranks of the price-to-sales ratio, price-earnings ratio, enterprise-value-to-EBITDA (EV/EBITDA) ratio, shareholder yield, price-to-book-value ratio and price-to-free-cash-flow ratio. The score is variable, meaning it can consider all six ratios or, should any of the six ratios not be valid, the remaining ratios that are valid. To be assigned a Value Score, stocks must have a valid (non-null) ratio and corresponding ranking for at least two of the six valuation ratios.

Stocks with a Value Score from 81 to 100 are considered deep value, those with a score between 61 and 80 are a good value and so on.

Pfizer Inc. has a Value Score of 71, which is Value. Merck & Co., Inc. has a Value Score of 39, which is Expensive.

The Value Stock Winner: Pfizer Inc.

As you can clearly see from the Value Grade breakdown above, Pfizer Inc. is considered to have better value than Merck & Co., Inc.. For investors who focus solely on a company’s valuation, Pfizer Inc. could be a good stock to add to their portfolio. However, it’s important for investors to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Pfizer Inc., Merck & Co. and Inc.’s Quality Grades

Company	Ticker	Quality
Pfizer Inc.	PFE	A
Merck & Co., Inc.	MRK	B

Like the Value Grade, AAII’s A+ Investor Quality Grade comes from the percentile rank of key metrics. Specifically, the Quality Score is the percentile rank of the average of the percentile ranks of return on assets (ROA), return on invested capital (ROIC), gross profit relative to assets, buyback yield, change in total liabilities to assets, accruals, Z double prime bankruptcy risk (Z) score and the F-Score.

The score is variable, meaning it can consider all eight measures or, should any of the eight measures not be valid, the remaining measures that are valid. To be assigned a Quality Score, stocks must have a valid (non-null) measure and corresponding ranking for at least four of the eight quality measures.

The Quality Score is used to assess the underlying “quality” of a particular stock. A higher-quality stock possesses traits associated with upside potential and reduced downside risk. Backtesting of the Quality Grade shows that stocks with higher grades, on average, outperformed stocks with lower grades over the period of 1998 through 2019.

Stocks receive better grades (higher scores) for having higher scores for the quality subcomponents and worse grades (lower scores) for lower scores for the subcomponents.

Pfizer Inc. has a Quality Score of 86, which is Very Strong. Merck & Co., Inc. has a Quality Score of 79, which is Strong.

The Quality Grade Winner: Pfizer Inc.

As you can clearly see from the Quality Grade breakdown above, Pfizer Inc. has a better overall quality grade than Merck & Co., Inc.. For investors who are looking for companies with higher quality than others in the same industry, Pfizer Inc. could be a good stock to add to their portfolios. However, it’s important for investors to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Pfizer Inc., Merck & Co. and Inc.’s Estimate Revisions Grades

Company	Ticker	Earnings Estimate
Pfizer Inc.	PFE	B
Merck & Co., Inc.	MRK	C

Earnings estimate revisions scores consider the magnitude of a company’s earnings surprise in its last two reported fiscal quarters. Often, positive surprises beget further positive surprises‐or at least continued sales growth (the exact opposite is generally true, too).

Estimate revisions offer an indication of what analysts are thinking about the short-term prospects of a firm. Estimate revisions are based on the statistical significance of a firm’s last two quarterly earnings surprises and the percentage change in its consensus estimate for the current fiscal year over the past month and past three months.

Pfizer Inc. has a Earnings Estimate Score of 63, which is Positive. Merck & Co., Inc. has a Earnings Estimate Score of 45, which is Neutral.

The Earnings Estimate Revisions Grade Winner: Pfizer Inc.

As you can clearly see from the Earnings Estimate Revisions Grade breakdown above, Pfizer Inc. has a better Earnings Estimate Revisions Grade than Merck & Co., Inc.. For those who are specifically looking for companies with better short-term prospects when compared to other companies in the same industry, Pfizer Inc. could be a good stock to invest in. However, it’s important to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Other Pfizer Inc., Merck & Co. and Inc. Grades

In addition to Estimate Revisions, Quality and Value, A+ Investor also provides grades for Growth and Momentum.

Momentum grades help uncover stocks experiencing anomalously high rates of return; research finds that stocks with high relative levels of momentum tend to outperform, whereas those with low levels of momentum tend to continue underperforming.

Growth investing builds on the idea that stocks of companies exhibiting strong, consistent and prolonged growth outperform those of slower-growth companies. AAII measures growth through consistency of annual sales growth, five-year sales growth rankings adjusted for extreme levels, and consistency of positive annual cash from operations.

These 2 key factors, when combined with the above, provide a holistic view into a particular stock. Further, by joining A+ Investor you can see whether Pfizer Inc., Merck & Co. and Inc. pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, Pfizer Inc., Merck & Co. or Inc. Stock?

Overall, Pfizer Inc. stock has a Value Score of 71, Estimate Revisions Score of 63 and Quality Score of 86.

Merck & Co., Inc. stock has a Value Score of 39, Estimate Revisions Score of 45 and Quality Score of 79.

Comparing Pfizer Inc., Merck & Co. and Inc.’s grades, scores and metrics can act as a solid basis to determine whether they may be a good investment or not. You’ll also want to look at your portfolio’s asset allocation as well as your risk tolerance and financial goals to see if either of these stocks would make a good fit for you. AAII can help you figure out which investments align with your individual needs and preferences.

Investors are encouraged to do their own due diligence and research. In this way, individuals can effectively become managers of their own assets‐without having to rely on others for financial independence. You can count on AAII for timeless articles on financial planning and stock-picking, unbiased research and actionable analysis.

A+ Investor adds to our qualitative teaching with a powerful data suite to help you whittle down investment choices to find stocks, exchange-traded funds (ETFs) or mutual funds that meet your needs.

AAII Disclaimer

We make no representations or warranties that any investor will, or is likely to, achieve profits similar to those shown, because past, hypothetical or simulated performance is not necessarily indicative of future results. Before making an investment decision, you should consider your circumstances and whether the information on our content is applicable to your situation. This information was prepared in good faith, and we accept no liability for any errors or omissions. The full disclaimer can be read here.