ABT vs MRK: Which Is the Better Buy in 2026?

Last updated October 2026

Short answer

MRK is the larger of the two ($360.08B market cap): the incumbent the market prices for continued execution (15.66x forward earnings, beta 0.22). ABT is the smaller challenger ($182.70B), priced similarly on forward earnings (17.29x): more room to run, but more to prove. The real question is which set of drivers you believe, and whether owning one (or both) leaves you over-concentrated.

ABT vs MRK: the tie-breaker metrics

Same yardstick, side by side (as of October 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

Metric	ABT	MRK	What it tells you
Market cap	$182.70B	$360.08B	Size. The larger name is the incumbent; the smaller has more room to grow and more to prove.
Forward P/E	17.29	15.66	Valuation on next year's expected earnings, the same yardstick for both. Lower is cheaper for that growth; higher means the market is paying up.
Trailing P/E	33.84	115.83	Valuation on the last 12 months. A big drop from trailing to forward means the market expects earnings to jump, so more growth is already in the price.
Beta	0.58	0.22	Volatility vs the market. Above 1 swings harder than the index; below 1 is steadier. Higher beta means bigger drawdowns to hold through.
Price vs 52-week range	46% of range	85% of range	Where today's price sits between the 52-week low and high. Near the high is momentum with less margin of safety; near the low is out of favor or a discount, depending on why.
Price / book	3.55	8.59	How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price.

Before you buy: how ABT and MRK affect your concentration

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. ABT and MRK share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined ABT and MRK exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

What does Abbott Laboratories (ABT) do?

Abbott Laboratories is a global healthcare company headquartered in North Chicago, Illinois, that discovers, develops, manufactures, and sells health care products in more than 160 countries through four segments: Medical Devices, Diagnostic Products, Nutritional Products, and Established Pharmaceutical Products. Medical Devices, the largest segment at roughly $21.4 billion in 2025 revenue, includes the FreeStyle Libre family of continuous glucose monitors, structural heart products (Navitor, TriClip), electrophysiology systems (AVEIR leadless pacemaker, Volt pulsed field ablation, TactiFlex Duo), vascular devices, and heart-failure technologies (CardioMEMS). Diagnostics contributed roughly $8.9 billion in 2025 before the Exact Sciences deal, Nutrition roughly $8.5 billion (anchored by Similac infant formula and Ensure adult nutrition), and Established Pharmaceuticals roughly $5.5 billion in branded generics sold primarily in emerging markets.

Full ABT guide

What does Merck & Co. (MRK) do?

Merck and Co., Inc. (NYSE: MRK) is a global research-intensive biopharmaceutical company headquartered in Rahway, New Jersey. It discovers, develops, manufactures, and markets prescription medicines, vaccines, and biologic therapies across oncology, infectious disease, cardiovascular, and diabetes, alongside a substantial Animal Health segment that sells vaccines and medicines for livestock and companion animals. The company operates under the MSD name outside the United States and Canada. Revenue flows primarily from pharmaceutical product sales, with oncology representing more than 60 percent of pharmaceutical revenue. Keytruda, a PD-1 inhibitor approved in more than 40 cancer indications, is the world's best-selling drug and the dominant revenue driver. Other meaningful contributors include the Gardasil HPV vaccine franchise, pulmonary arterial hypertension therapy Winrevair, pneumococcal vaccine Capvaxive, antiviral Lagevrio, and the Animal Health portfolio led by the Bravecto parasite treatment and Allflex livestock intelligence products.

Full MRK guide

ABT vs MRK: how do they differ?

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

ABT drivers: FreeStyle Libre: A Platform, Not Just a Product; Cardiovascular and Electrophysiology Momentum.
MRK drivers: Keytruda's remaining runway is substantial; A tripling of the Phase III pipeline provides post-cliff optionality.

Which fits which kind of investor

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The most acute near-term risk is infant formula litigation: juries have delivered verdicts including a $53 million compensatory award in late March 2026 and a separately upheld $495 million verdict, with hundreds of additional NEC-related cases pending, and a securities class action filed in 2026 adds a parallel legal exposure track targeting alleged investor misstatements. For MRK, the central risk is Keytruda concentration: the drug accounts for roughly half of total company revenue, and its primary U.S.

ABT or MRK: which should you pick?

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick ABT if you believe its drivers more; MRK if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the ABT and MRK guides.

ABT vs MRK: the full fundamentals

ABT. ABT's trailing GAAP P/E of about 34x is inflated by acquisition amortization and one-time costs from the Exact Sciences deal; on forward earnings the stock trades near 17x, well below its own 5-year and 10-year historical averages, after a roughly 16% decline in 2026. Revenue growth has remained positive, and the raised adjusted EPS guidance of $5.45-$5.60 implies a forward adjusted P/E of about 19x at the October 16 price of $104.44, below the average analyst target of about $121. Q3 2026 results are due October 21, with company guidance of $1.38-$1.46 adjusted EPS and consensus near $1.41 on about $13.0 billion of sales.

MRK. Merck's trailing P/E near 117x is an artifact of 2026 acquisition charges that pushed GAAP results into losses in the first half; the forward P/E of about 15.8x on 2027 consensus EPS of about $9.32 is the more useful yardstick, and it sits below the mid-30s trailing multiple the stock carried in mid-2026 on clean earnings. The market has rewarded the pipeline and new launches with a 38% gain this year, so the October 29 Q3 report (consensus EPS about $2.09) and updated guidance matter for whether that rerating holds. The 25 analysts Yahoo Finance tracks have a mean target near $159.

Headline figures (approximate, October 2026): ABT shows revenue (ttm) ~$46.6 billion (Q2 2026 sales $12.59 billion, +13% reported, +4.8% comparable), revenue (fy 2025) ~$44.3 billion (+5.7% YoY), net income (ttm) ~$5.4 billion (GAAP EPS ~$3.10), net profit margin (ttm) ~11.7%; MRK shows revenue (ttm) ~$66.6 billion (Q2 2026 +5.1% YoY), net income (ttm, gaap) ~$3.2 billion, after 2026 acquisition charges (FY2025: ~$18.3 billion), gross margin (ttm) ~75.9%, p/e (trailing / forward) ~117x / ~15.8x.

The bottom line: ABT vs MRK

ABT and MRK are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined ABT and MRK exposure against your real portfolio. It is not an investment adviser.

Wondering how ABT or MRK fits the portfolio you already own? Walnut is an AI investing app that connects your brokerage read-only and answers questions like that about your actual holdings: overlap, concentration, and how each position tracks the S&P 500. Compare the best AI portfolio analyzers or see the best AI investing apps in 2026.

Investing in Abbott Laboratories with AI

Connect the broker you already use and ask Walnut's AI how ABT fits what you actually hold: whether you own it already through a fund, what it would do to your concentration, and how it has tracked the S&P 500. Read-only by default, and you approve anything before it reaches your broker.

Does ABT fit me?

FAQ

What is the difference between ABT and MRK?

Is ABT or MRK the better stock?

Neither is universally better. MRK is the larger incumbent; ABT is the smaller challenger and looks pricier on forward earnings. Walnut is informational, not investment advice. Compare what each does, the tie-breaker metrics above, and the risks, then decide which fits your thesis and what you already own.

Which is cheaper, ABT or MRK?

On forward P/E (as of October 2026), ABT trades at 17.29x and MRK at 15.66x, so MRK is the cheaper of the two on next year's expected earnings. A lower multiple is not automatically the better buy: a richer valuation can be justified by faster growth, and a lower one can reflect real risk. Weigh the multiple against how fast each business is compounding.

Should you own both ABT and MRK?

Because they share themes, owning both concentrates you in that theme. That can be intentional (a focused bet) or accidental (less diversification than it looks). Walnut can show your combined exposure across both, and whether adding either over-concentrates you, before you buy.

What are the risks of ABT vs MRK?

ABT: The most acute near-term risk is infant formula litigation: juries have delivered verdicts including a $53 million compensatory award in late March 2026 and a separately upheld $495 million verdict, with hundreds of additional NEC-related cases pending, and a securities class action filed in 2026 adds a parallel legal exposure track targeting alleged investor misstatements. Abbott has started to narrow this exposure, reaching agreements in August 2026 to resolve a portion of the preterm-formula litigation and an agreement with the Department of Justice in September 2026 on claims tied to the 2022 recall, but the remaining liability is still open-ended. Integration of the approximately $21 billion Exact Sciences acquisition introduces execution risk, amortization and elevated SGA costs: GAAP EPS was only $0.53 in Q2 2026 against adjusted EPS of $1.31, and the trailing GAAP P/E is about 34x even though the forward multiple is about 17x. Organic growth also slowed to 4.8% in Q2 2026 on a comparable basis, below the full-year 6.5-7.5% guide. Foreign exchange swings move reported international revenue by several percentage points, and any meaningful dollar strengthening would pressure reported results disproportionately given Abbott's broad non-US exposure. Competitive disruption in continuous glucose monitoring from DexCom and emerging players, along with pricing pressure from government payers and the Inflation Reduction Act, represent structural long-term headwinds. MRK: 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. A newer risk is valuation after the rally: the stock rose about 75% in a year to roughly 16 times 2027 consensus EPS, total debt has grown to about $54 billion against about $7 billion of cash, and Goldman Sachs trimmed its price target to $155 from $160 in October 2026. Walnut is not an investment adviser.

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Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell ABT or MRK; figures are approximate and dated (as of October 2026). Verify current data before investing.