Daily close, T-120 (5/8/25) through T+5. Run-up high $45.51 on 10/1/25, low $36.2 on 7/22/25 (T-120 to T-1). FDA decision 10/23/25. Historical price action, not a forecast.
Positioning before the decision
On Oct 9, 2025, 14 days before the decision date, at-the-money options priced a move of ±5.7% through Oct 24, 2025 (the first listed expiry after the decision; ATM implied volatility 35%). The stock closed +2.9% at the first close across the decision and +3.8% five trading days on. A straddle priced weeks out covers ordinary movement plus the event, so this is the move the options market priced through that expiry, not the event-implied move alone. How this compares across 1,000+ decisions.
Yes. The FDA approved the application for Blenrep on October 23, 2025. The primary source is linked on this page.
What was Blenrep under FDA review for?
The application covered Multiple myeloma. The FDA approved the application on October 23, 2025.
How did GSK stock react to the FDA decision?
On the decision day GSK moved +2.9%. That is the recorded reaction to this specific event -- historical measurement, not a prediction, and not investment advice.