ALT ▼ -0.3% - Altimmune, Inc. $ALT - Altimmune to Participate in Stifel Cardiometabolic Forum Altimmune shares declined 0.3% today ahead of the company's participation in the Stifel Cardiometabolic Forum, an investor event where the biotech firm will present updates on its pipeline. Conference presentations can draw investor attention to clinical progress or partnership developments, though today's modest decline suggests limited immediate market reaction to the announcement. 23-SEP-2026 08:01 AM ET