Summit Therapeutics is trading 4.37% lower at $15.33, with no confirmed catalyst identified for the November 2 decline. - The stock is falling while major U.S. indices are higher, so the broader market rebound does not explain the move. - Investors may be watching the company’s Q3 report, but available sources do not establish it as the cause. - Recent coverage discussed interest in ivonescimab collaborations, not negative news tied to this decline.