Daily close, T-120 (10/24/24) through T+5. Run-up high $671.745 on 2/6/25, low $540.61 on 10/24/24 (T-120 to T-1). FDA decision 4/10/25. Historical price action, not a forecast.
Positioning before the decision
On Mar 27, 2025, 14 days before the decision date, at-the-money options priced a move of ±6.7% through Apr 17, 2025 (the first listed expiry after the decision; ATM implied volatility 35%). The stock closed -3.2% at the first close across the decision and +4.2% 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.
Was VYVGART Hytrulo (efgartigimod) approved by the FDA?
Yes. The FDA approved the application for VYVGART Hytrulo (efgartigimod) on April 10, 2025. The primary source is linked on this page.
What was VYVGART Hytrulo (efgartigimod) under FDA review for?
The application covered Generalized myasthenia gravis (gMG), chronic inflammatory demyelinating polyneuropathy (CI. The FDA approved the application on April 10, 2025.
How did ARGX stock react to the FDA decision?
On the decision day ARGX moved -3.2%. That is the recorded reaction to this specific event -- historical measurement, not a prediction, and not investment advice.