The mechanism. Wall Street reads Gilead's lenacapavir (Yeztugo) as a clinical slam dunk: a twice-yearly PrEP shot with best-in-class efficacy, priced at roughly $28,218 a year in the U.S. commercial market. But the volume that makes lenacapavir a category-defining franchise — not just a niche PrEP brand — comes from PEPFAR and the Global Fund, which are procuring it at no profit to Gilead for up to 2-3 million people across high-burden countries through 2028. That deal only exists because Congress keeps funding it. PEPFAR has run on one-year reauthorizations since its 2024 lapse, missing multiple deadlines and surviving mostly on continuing appropriations rather than a clean multi-year law. Every appropriations cycle is now a go/no-go vote on whether Gilead's global access strategy — the thing analysts credit with derisking lenacapavir's long-term market position ahead of 2027 generic entry — keeps running at scale.