GMAB vs SNY: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 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.

Reading it: SNY is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.

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. GMAB and SNY 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 GMAB and SNY 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.

Genmab A/S, founded in 1999 and headquartered in Copenhagen, engineers therapeutic antibodies and has historically licensed them to larger partners rather than selling them itself. The best known is daratumumab, sold by Johnson & Johnson as DARZALEX and DARZALEX FASPRO, which has become a backbone therapy in multiple myeloma and pays Genmab a royalty on worldwide net sales. Genmab also earns royalties on ofatumumab (Kesimpta, Novartis) and teprotumumab (TEPEZZA), and shares in two commercial products it helped develop: epcoritamab, sold as EPKINLY in the US and TEPKINLY in Europe with AbbVie, and tisotumab vedotin (TIVDAK) with Pfizer. The strategic shift under way is toward owning products outright. Rina-S (rinatabart sesutecan), a folate receptor alpha antibody-drug conjugate in ovarian cancer, is wholly owned, and the December 2025 close of the $8 billion all-cash acquisition of Merus N.V. at $97 per share added petosemtamab, a late-stage bispecific in head and neck cancer.

Full GMAB guide

Sanofi S.A. is one of the world's largest pharmaceutical companies, based in France and organized around biopharma (specialty care, general medicines) and vaccines. Its single most important product is Dupixent, an immunology drug co-developed with Regeneron that treats conditions like eczema, asthma, and COPD; Dupixent sales moved above the roughly four-billion-euro-per-quarter mark in Q1 2026 and grew more than 30% year over year, making it the engine of the company's revenue growth. Sanofi also runs a major vaccines business (including the RSV antibody Beyfortus and the newly acquired hepatitis-B vaccine Heplisav-B) and spun off its consumer-health arm, Opella (Allegra, Icy Hot, Dulcolax), in 2025 to focus purely on innovative medicines and vaccines.

Full SNY guide

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

• GMAB drivers: DARZALEX royalties still compounding; EPKINLY as the first real commercial franchise.
• SNY drivers: Dupixent as the growth engine; Pipeline and new launches.

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: Revenue concentration is the first-order risk: DARZALEX royalties were roughly 64% of first-half 2026 revenue, Genmab does not control how the drug is priced or promoted, and daratumumab exclusivity does not last forever, so the whole equity story is a race between pipeline conversion and eventual biosimilar erosion. For SNY, the clearest risk is concentration in Dupixent: with one product carrying so much of the growth, its eventual loss of patent exclusivity later this decade is the central overhang, and the pipeline may or may not fully replace it.

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 GMAB if you believe its drivers more; SNY 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 GMAB and SNY guides.

GMAB. Figures are approximate and tied to the asOf date; verify live numbers before acting. Genmab is unusual for a mid-cap biotech in being consistently profitable, because the royalty line carries almost no cost, so screening it on earnings multiples against pre-revenue biotech peers is not informative. The more useful framing is that a large share of current profit comes from an asset Genmab neither sells nor controls, so the multiple reflects a market judgment on the wholly owned pipeline rather than on the current royalty. Reported profit also now absorbs the operating costs and accounting effects of the Merus acquisition, which is why adjusted operating profit and reported operating profit have separated.

SNY. Figures are approximate, drawn from public 2026 reporting, and tied to the asOf date; verify live numbers before acting. Sanofi reports in euros, so the dollar value of SNY and its dividend also depends on the euro-to-dollar exchange rate. As a defensive large-cap pharma, the stock tends to trade on pipeline news, Dupixent momentum, and the eventual patent-expiry timeline rather than on sharp cyclical swings.

Headline figures (approximate, August 2026): GMAB shows revenue (ttm) ~$4.1 billion, presented in US dollars (H1 2026 was ~$2.05 billion, up ~25% year over year), darzalex royalties (h1 2026) ~$1.31 billion, up ~20%, roughly 64% of total revenue, owned and shared product sales (h1 2026) EPKINLY and TEPKINLY ~$312 million (up ~48%), TIVDAK ~$84 million, profitability (h1 2026) Operating profit ~$555 million; adjusted operating profit ~$656 million; SNY shows company type Large-cap, diversified global pharmaceutical company (French, US-listed as an ADR on Nasdaq), market cap ~$107 billion (approximate; among the larger global pharma names), q1 2026 revenue ~10.5 billion euros, ahead of consensus (reported figures are in euros), q1 2026 business eps ~1.88 euros, up ~14% at constant exchange rates.

GMAB and SNY 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 GMAB and SNY exposure against your real portfolio. It is not an investment adviser.