Karyopharm Therapeutics' stock price is primarily driven by clinical trial data readouts, regulatory update milestones for its drug pipeline, and quarterly commercial sales reports for its flagship oncology product, XPOVIO. Investor sentiment fluctuates based on progress updates concerning late-stage clinical trials targeting indications such as myelofibrosis and endometrial cancer. Additionally, broader biotechnology sector sentiment, capital-raising announcements, and debt restructuring activities heavily impact its short-term market valuation.