Altimmune is trading 5.36% lower at $3.23, with the decline appearing primarily linked to broad risk-off conditions. - The Nasdaq Composite is down 1.03%, while rising oil prices and Treasury yields are pressuring equity valuations. - Biotech is higher, making sector weakness a less likely explanation for Altimmune’s decline. - Altimmune announced participation in the Stifel 2026 Virtual Cardiometabolic Forum on September 30; the routine notice offers no clear negative company-specific catalyst.