HALOZYME THERAPEUTICS, INC. (HALO) stock intrinsic value fair value estimate & owner earnings analysis

Halozyme licenses a drug-delivery technology called ENHANZE to large pharmaceutical companies, who use it to convert their intravenous infusion drugs into quick, under-the-skin injections. Halozyme doesn't sell these drugs itself -- it collects a royalty on its partners' sales. Partners currently using the technology include Janssen (Johnson & Johnson), on Darzalex Faspro, its top revenue source at roughly 41% of sales, and Roche, on products including Phesgo and Tecentriq SC, at roughly 17%. A newer partnership with argenx, on Vyvgart Hytrulo, has grown quickly, from about 7% of revenue in 2023 to 16% in 2025. Halozyme also owns Antares Pharma, an auto-injector device maker acquired in 2022, which contributes product revenue alongside the royalty stream. In November 2025, Halozyme spent $810 million to acquire Elektrofi, a company developing an early-stage, not-yet-clinically-proven technology for concentrating drugs into smaller injection volumes; because this technology has no approved products or contracted revenue yet, we have not given it credit in any of the three cases below -- only proven, revenue-generating parts of the business are valued. The royalty business has grown enormously as partnered drugs have won new approvals and expanded into new patient groups -- most recently, Darzalex Faspro received a new FDA approval as recently as January 2026. Owner earnings (cash profit after removing the swings from working capital, stock-based pay, and the investment needed just to maintain the business) have gone from about $2.14 per share in 2022, the first full year including Antares, to $2.81 in 2023, $3.99 in 2024, and $6.04 in 2025 -- a 52% jump in the most recent year alone, helped both by the royalty ramp and by shares outstanding shrinking through buybacks. We've anchored this valuation on the median of the three most recent full years since Antares was folded in ($3.99 per share, the 2024 figure), rather than the latest, strongest year, because a single blowout year is not yet proven to be the new normal. Because the trailing growth rate (52%) is unusually high, we assumed meaningfully slower growth in year one of our base case (about 18%) than the company just delivered. Two dated facts support that: the Elektrofi purchase absorbs cash that would otherwise likely go to buybacks, and Halozyme raised $1.5 billion in new convertible debt in November 2025 to help fund it, on top of $680 million of debt already outstanding -- a combined $2.1 billion, which will need to be serviced with cash. Under our base case, growth decelerates gradually over ten years as the royalty base matures, settling into a low single-digit pace after that, in recognition of the fact that Halozyme's royalty rates step down under its contracts once its own patents on the technology expire in a given country, even though the underlying licensing relationships and payment terms often continue. Our bear case assumes the risks already visible in the filings show up in the numbers: royalty growth stalls as those patent-related rate reductions bite, competitive or growth pressure emerges around the lead partner relationship, and the new debt load and integration costs limit the pace of further buybacks. In this case, owner earnings per share are roughly flat to slightly declining over the next couple of years before stabilizing. Our bull case assumes the business's own demonstrated pattern keeps working well -- continued approvals across the existing partner roster (as has happened repeatedly for over a decade), faster ramps for newer launches like Vyvgart Hytrulo, and a return to a brisk pace of buybacks once the recent acquisition is digested. On these assumptions, discounted at a flat 6%, we estimate the shares are worth roughly $67 in the bear case, $160 in the base case, and $262 in the bull case. Given the real risks around patent-linked royalty step-downs, meaningful concentration in a small number of partners, and $2.1 billion of debt taken on partly to fund an unproven technology bet, the margin-of-safety price is set meaningfully below our base-case estimate -- around $90 per share -- to build in a healthy margin of safety; evidence that the company is prioritizing the proven royalty business over further speculative acquisitions would support a higher figure. One item we could not fully reconcile from the filings: the exact calendar-year timing of individual country-by-country patent expirations for the core technology was not disclosed with specific dates, so the pace of the royalty step-down risk is a judgment call rather than a precisely dated one.