ALT vs HALO: 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. ALT and HALO 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 ALT and HALO 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.

Altimmune is a clinical-stage biopharmaceutical company focused on metabolic and liver disease. Its lead candidate, pemvidutide, is a dual agonist of the GLP-1 and glucagon receptors designed to drive weight loss while preserving lean mass and improving liver health. The company has run a Phase 2 obesity program (MOMENTUM) and a Phase 2b MASH program (IMPACT), and reported positive 48-week topline MASH results in December 2025 showing significant improvements in liver fat, weight, and fibrosis markers versus placebo.

Full ALT guide

Halozyme Therapeutics licenses drug delivery technology instead of selling many drugs of its own. Its core asset is rHuPH20, a recombinant human hyaluronidase branded ENHANZE, which temporarily breaks down hyaluronan in the subcutaneous space so a large-volume biologic can be injected under the skin in minutes rather than infused for hours. Roche, Janssen, Takeda, argenx, Pfizer, AbbVie, Eli Lilly, Bristol-Myers Squibb, GSK and Incyte are among the licensees, and ENHANZE now sits inside ten commercialized products across more than 100 markets. Halozyme takes upfront and milestone payments plus royalties averaging a mid-single-digit percentage of partner sales, and it separately sells bulk rHuPH20 to those partners, plus two proprietary products (Hylenex and XYOSTED) and auto-injector devices inherited from the Antares Pharma acquisition.

Full HALO guide

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

• ALT drivers: Differentiated GLP-1/glucagon profile; MASH opportunity.
• HALO drivers: Royalty compounding from products launched since 2020; New deal signings and the hyperconcentration platforms.

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: Altimmune is a single-asset, clinical-stage company with no approved products and no revenue, so a failed or disappointing Phase 3 readout could sharply reduce the stock. For HALO, the 2027 US rHuPH20 patent expiry is a dated, contractually specified step-down in royalty rates in countries where no other valid claim covers a partner product, and no amount of revenue growth removes that clock.

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 ALT if you believe its drivers more; HALO 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 ALT and HALO guides.

ALT. As a pre-revenue biotech, Altimmune cannot be valued on earnings or P/E; its market value reflects the probability-weighted commercial potential of pemvidutide. The roughly $535 million cash position is a key strength because it funds expensive Phase 3 work, but the eventual value depends on trial outcomes and approval, both of which are uncertain.

HALO. The stock rose about 20% on August 7, 2026 after Q2 results beat and guidance was raised for total revenue, royalties, adjusted EBITDA (~$1.225B to ~$1.280B) and EPS. At roughly $103 that is about 30 times trailing GAAP earnings, which are depressed by the ~$284.9 million in-process R&D charge and ~$48.7 million intangible impairment taken in Q4 2025, and closer to 12 times the midpoint of 2026 non-GAAP EPS guidance. On an enterprise basis (~$13.6B including net debt) the shares trade near 7 times guided 2026 revenue and roughly 11 times guided adjusted EBITDA, a multiple that embeds some expectation that royalties survive the 2027 patent step-down.

Headline figures (approximate, Q1 2026): ALT shows product revenue None (clinical-stage), cash + short-term investments ~$535 million, lead program Pemvidutide (obesity, MASH), mash stage Phase 3 (PERFORMA) planned H2 2026; HALO shows revenue (ttm) ~$1.66B, royalty share of revenue (q2 2026) ~64% (~$307.7M of ~$481.0M), 2026 revenue guidance (raised aug 6) ~$1.835B to ~$1.910B, 2026 non-gaap diluted eps guidance ~$8.65 to ~$9.00.

ALT and HALO 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 ALT and HALO exposure against your real portfolio. It is not an investment adviser.