Merck & Co. Inc. stock (US58933Y1055): oncology growth meets new M&A financing

Merck & Co. Inc. has returned to the bond market, with S&P Global Ratings assigning a rating to new senior unsecured notes that the drugmaker plans to use for general corporate purposes, including funding its proposed $5.7 billion acquisition of Terns Pharmaceuticals. The deal underscores Merck’s strategy of bolstering its oncology and immunology pipeline alongside existing blockbusters, according to S&P Global Ratings as of 05/13/2026.

On the equity side, Merck shares recently traded around the low?$110 range on the New York Stock Exchange, with MarketBeat citing a price of about $111.36 on May 15, 2026 and an implied upside to a consensus target near $128 based on surveyed analysts, according to MarketBeat as of 05/15/2026. That backdrop, combined with a steady dividend and large?cap defensive profile, keeps the stock in focus for US healthcare investors.

As of: 05/18/2026

By the editorial team – specialized in equity coverage.

Merck & Co. Inc.: core business model

Merck & Co. Inc. is one of the largest global research?driven pharmaceutical companies, with a business model centered on discovering, developing, manufacturing and marketing innovative medicines and vaccines for human and animal health. The company’s portfolio spans oncology, vaccines, infectious diseases, cardiometabolic conditions and hospital acute care. It also maintains a meaningful animal health division offering veterinary pharmaceuticals, vaccines and services to livestock and companion animal markets.

In recent years, Merck’s strategy has focused on high?value therapeutic areas where it can build durable franchises supported by strong intellectual property and clinical data. Oncology, particularly immuno?oncology, has become the company’s flagship growth driver, while vaccines such as those for human papillomavirus and pediatric diseases remain important cash generators. This focus on innovation is backed by significant research and development spending, with annual R&D outlays running into the tens of billions of dollars across multiple late?stage programs, as highlighted in the company’s recent annual filings and earnings materials published in 2024.

Merck also operates a global commercial infrastructure, selling products in more than 140 countries through a combination of internal sales teams, distributors and partnerships. Pricing dynamics remain a key consideration in its business model, particularly in the United States, where policy reforms around drug pricing, Medicare negotiations and biosimilar competition can influence revenues. To mitigate such pressures, Merck aims to diversify its portfolio, expand into earlier?stage disease treatment and prevention, and pursue lifecycle management for existing drugs through new indications, formulations and combinations.

Another pillar of the business model is disciplined capital allocation, which balances sizable R&D investments with shareholder returns and inorganic growth. Merck returns cash through dividends and share repurchases, while keeping room for mergers, acquisitions and licensing deals that enhance its pipeline. The company’s recent decision to raise senior unsecured notes to help fund the planned Terns Pharmaceuticals acquisition signals a continuation of this approach, with management seeking to add assets in areas such as nonalcoholic steatohepatitis and oncology that could complement its existing capabilities, according to S&P Global Ratings as of 05/13/2026.

Main revenue and product drivers for Merck & Co. Inc.

Merck’s revenue base is concentrated in a relatively small number of blockbuster products, especially in oncology and vaccines. The immuno?oncology therapy Keytruda has been the principal growth engine, with the company reporting double?digit sales expansion for the drug in its 2023 annual report released in February 2024, driven by uptake in lung, melanoma and other cancer indications. Keytruda’s broad label, spanning adjuvant and metastatic settings, gives Merck exposure to multiple tumor types and treatment lines, making it central to earnings and cash flow.

Beyond oncology, Merck generates substantial revenue from vaccines such as Gardasil for human papillomavirus prevention and from pediatric and adolescent vaccines. These franchises benefit from public health programs and inclusion in immunization schedules across many countries, which provide some visibility on demand. In the 2023 reporting period, vaccines collectively contributed a sizable share of the company’s total pharmaceutical sales, according to the annual results published in early 2024; this segment also tends to be less exposed to generic erosion than traditional small?molecule drugs.

Merck’s animal health division is another meaningful contributor, offering parasiticides, vaccines and other products for livestock and pets. While smaller than the human health business, animal health generates relatively stable recurring revenue tied to global protein consumption and pet ownership trends. The company has indicated in past quarterly reports that animal health margins are attractive and that the segment can be a steady cash generator, which helps balance the higher volatility associated with patent?protected human pharmaceuticals.

Looking forward, the planned acquisition of Terns Pharmaceuticals is aimed at strengthening Merck’s development pipeline in metabolic and liver diseases and potentially expanding its footprint in adjacent therapeutic areas. S&P Global Ratings noted that Merck intends to use proceeds from its newly rated senior unsecured notes for general corporate purposes, including this $5.7 billion transaction, and that the company is expected to maintain a strong balance sheet and credit profile after the deal, as outlined in its May 2026 rating report. For equity investors, such moves indicate that Merck is using both internal R&D and targeted M&A to sustain long?term revenue growth beyond the current blockbuster portfolio.

Conclusion

Merck & Co. Inc. combines a leading oncology and vaccine portfolio with a strategy of reinvesting heavily in research, while selectively using debt markets to fund acquisitions such as the planned purchase of Terns Pharmaceuticals. The recent senior unsecured notes, rated by S&P Global Ratings, suggest that credit quality remains solid even as the company pursues pipeline?enhancing deals. For US investors, the NYSE?listed large cap offers exposure to global healthcare demand, but also faces familiar sector risks around patent expirations, regulatory changes and competitive launches. How effectively Merck manages its pipeline, capital allocation and upcoming patent cliffs will shape the stock’s long?term risk?reward profile.

Disclaimer: This article does not constitute investment advice. Stocks are volatile financial instruments.