Spero Therapeutics is trading at $1.27, up 5.37%, with no specific reason for the move established for October 1, 2026. - No clear company-specific announcement was found; recent headlines surfaced in search were earlier announcements, not a new event explaining the gain. - Broader markets were mixed, and rising Treasury yields pressured equities. Supplied index moves were modest and opposite Spero Therapeutics’ direction, offering no clear explanation. - Volume information was unavailable.