Is MRK a Buy or a Sell? The Bull and Bear Case (2026)

That depends on which case you find more convincing, and both are on this page. The bull case rests on Keytruda's remaining runway is substantial, with revenue (fy 2025) at ~$65.0 billion. The bear case rests on the central risk is Keytruda concentration: the drug accounts for roughly half of total company revenue, and its primary U.S. Analysts covering it are spread from $105.00 to $155.00, which is itself a signal that this is genuinely contested. If you believe the thesis, the real questions become sizing and overlap rather than timing. Walnut is not an investment adviser and this is not a recommendation.

Nobody can answer that for you, and the honest version of the question is narrower: has anything changed in the reason you bought it? The bear case on this page is the place to check. The central risk is Keytruda concentration: the drug accounts for roughly half of total company revenue, and its primary U.S. If that risk is what you were worried about and it is now playing out, that is a real signal. If the price simply fell while the thesis held, that is a different situation entirely. The most pessimistic published target is $105.00, -20.0% from the $131.22 price, which is one analyst's downside case rather than a floor. Walnut is not an investment adviser.

Keytruda's remaining runway is substantial. Keytruda recorded roughly $31.7 billion in sales in 2025, up 7 percent year over year, and management projects peak sales near $35 billion by 2028. The most optimistic analyst target on MRK is $155.00, +18.1% from the $131.22 price. That figure is only reachable if this thesis works close to its best case.

The central risk is Keytruda concentration: the drug accounts for roughly half of total company revenue, and its primary U.S. patents expire in late 2028, at which point biosimilars from companies including Celltrion and Samsung Bioepis are positioned to enter and compress pricing. This cliff is compounded by IRA Medicare price cuts already reducing Januvia reimbursement by 79 percent starting in 2026, creating a multi-billion-dollar annual headwind from drug pricing reform. Gardasil faces its own pressure from weak China demand and a CDC recommendation change that reduces the number of doses in the pediatric schedule, and near-term earnings growth is constrained by acquisition-related charges and tariff costs estimated at $200 million annually at current levels. The timing gap between Keytruda's revenue decline and the pipeline's commercial maturity, expected around the mid-2030s, is the key uncertainty investors must weigh. The most pessimistic published target is $105.00, -20.0% from the current price, which is roughly what the stock is worth if these risks bite rather than the drivers.

Merck and Co., Inc.

Decide that in advance, because it is far harder to think clearly once a position is moving against you. The concrete tripwires here: the driver behind the bull case (Keytruda's remaining runway is substantial) stalling in the reported numbers rather than in the narrative, the risk above (the central risk is Keytruda concentration: the drug accounts for roughly half of total company revenue, and its primary U.S) turning from a possibility into a reported fact, or the position growing large enough that a bad outcome would matter to your whole portfolio regardless of who is right.

Merck is a global biopharmaceutical company that discovers, develops, and sells prescription medicines, vaccines, and animal health products. Its largest business is human health pharmaceuticals, dominated by the cancer immunotherapy Keytruda, which accounts for roughly half of total revenue. Other key products include the Gardasil HPV vaccine, the Winrevair cardiovascular drug, and a large animal and companion animal health portfolio.

That depends on your time horizon and risk tolerance. Merck generates roughly $65 billion in annual revenue with strong margins and pays a dividend, but Keytruda's patent expiry in 2028 creates a known revenue cliff. Investors who believe the pipeline can bridge that gap may find the current valuation reasonable. Those with shorter horizons may prefer to wait for clearer evidence of post-cliff revenue diversification.

Yes. Merck has paid a quarterly dividend consistently for many years and has grown it for more than 15 consecutive years. As of mid-2026, the indicated quarterly dividend is $0.85 per share, implying an annual yield near 2.7 to 3 percent depending on share price. Dividend sustainability is supported by the company's strong operating cash flow, though the 2028 patent cliff is a factor long-term income investors should consider.