Cue Biopharma is trading 6.32% down at $34.71 after opening-market selling on September 21, 2026; no reliable source identifies a specific negative catalyst.
- The company reported positive Phase 2 CUE-221 results on September 20, including statistically significant efficacy and plans for a Phase 2b/3 study.
- Shares climbed from $28.00 on September 10 to $37.05 on September 18, suggesting possible profit-taking, though that explanation is unconfirmed.