SEPN vs VKTX: 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.

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. SEPN and VKTX 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 SEPN and VKTX 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.

Septerna, Inc. designs oral small molecule drugs against G protein-coupled receptors, the receptor family that sits behind roughly a third of approved medicines but which has historically been drugged with injectables or with molecules found by luck rather than by design. Its Native Complex Platform reconstitutes GPCRs outside the cell in a form stable enough to screen and to solve structurally, which is what lets the company go after targets that are usually reached with peptides or antibodies. Three efforts define the pipeline in 2026: SEP-631, an oral MRGPRX2 antagonist aimed at chronic spontaneous urticaria; SEP-479, a next-generation oral PTH1R agonist for hypoparathyroidism; and a global collaboration with Novo Nordisk on oral GPCR programs in obesity, type 2 diabetes and other cardiometabolic disease. The company listed on the Nasdaq in October 2024 with an upsized IPO that raised about $288 million.

Full SEPN guide

Viking Therapeutics (VKTX) is a clinical-stage biopharmaceutical company developing novel therapies for metabolic and endocrine disorders. Its highest-profile program is VK2735, a dual GLP-1 and GIP receptor agonist for obesity, being developed in both injectable and oral forms, which puts Viking among the most closely watched challengers in the booming weight-loss drug market dominated by Novo Nordisk and Eli Lilly. Viking is also developing VK2809, a thyroid-hormone receptor beta agonist for non-alcoholic steatohepatitis (NASH/MASH), and VK0214 for a rare disease (X-linked adrenoleukodystrophy). As a clinical-stage company, Viking has no approved products and generates essentially no product revenue, funding itself from cash on its balance sheet. Headquartered in San Diego, California, VKTX is a speculative, binary biotech whose value hinges on clinical-trial outcomes and the eventual commercial path for its lead obesity drug.

Full VKTX guide

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

• SEPN drivers: The Novo Nordisk collaboration; SEP-631 into Phase 2b.
• VKTX drivers: Lead obesity program (VK2735); Pipeline breadth in metabolic disease.

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: Every clinical-stage biotech carries binary risk, and here it has already been demonstrated: SEP-786 was discontinued in February 2025 after two severe cases of elevated unconjugated bilirubin, and the stock fell 47% that day. For VKTX, viking is a clinical-stage biotech with no approved products and essentially no product revenue, so it is highly speculative and potentially binary.

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 SEPN if you believe its drivers more; VKTX 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 SEPN and VKTX guides.

SEPN. Price to sales of roughly 22 times shows up on screeners, but the denominator is partnership revenue on a recognition schedule, so the ratio does not describe a commercial business and comparing it to a specialty pharma multiple is not meaningful. The more useful framing is enterprise value: about $2.2 billion of market cap against roughly $516 million of cash leaves close to $1.7 billion attributed to a pipeline whose most advanced asset is entering Phase 2b. Analysts covering the stock are clustered around $49 to $51 after the August 2026 target raises, which is close to where the shares already trade.

VKTX. Viking has no earnings to value on a P/E basis; the stock is priced on the probability-weighted potential of its pipeline, above all VK2735 in obesity, and on acquisition speculation. The shares are highly volatile and move sharply on trial readouts and deal rumors. Cash runway matters because additional fundraising could dilute holders. All figures are approximate and should be verified against current filings.

Headline figures (approximate, August 2026): SEPN shows revenue (ttm) ~$99 million, essentially all collaboration revenue from Novo Nordisk rather than product sales, revenue (q2 2026) ~$26.8 million versus consensus near $19.2 million, net loss (ttm) ~$24 million, or about $0.54 per share, cash ~$516.5 million at June 30, 2026, guided to fund operations at least into 2029; VKTX shows business stage Clinical-stage biotech, no approved products, lead program VK2735 (dual GLP-1/GIP agonist) for obesity, injectable + oral, other programs VK2809 (NASH/MASH), VK0214 (rare disease), product revenue ~$0 (no approved products).

SEPN and VKTX 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 SEPN and VKTX exposure against your real portfolio. It is not an investment adviser.