Argenx Stock Plummets 11.76% in Two Days Despite Vyvgart Sales Surpassing Forecasts Ranking 207th in Trading Volume

On May 9, 2025, Argenx (ARGX) experienced a significant decline, with its trading volume dropping by 64.25% to 3.96 billion, ranking 207th in the day's stock market activity. The stock price fell by 3.42%, marking the second consecutive day of decline, with a total decrease of 11.76% over the past two days.

Argenx's stock tumbled after the company's autoimmune disease drug, Vyvgart, exceeded first-quarter sales forecasts but fell short of investor expectations. Vyvgart, which treats generalized myasthenia gravis and chronic inflammatory demyelinating polyradiculoneuropathy, generated $790 million in sales, surpassing projections of $787 million. Despite this, the stock price declined, likely due to high investor expectations surrounding the launch of the CIDP indication.

Analysts noted that Vyvgart has shown consistent growth since its launch, with a 98% year-over-year increase in sales. The company's management highlighted that Vyvgart is expanding across all regions and product forms, including intravenous infusions, under-the-skin shots, and a recently approved prefilled syringe for home administration. This growth reflects strong demand and momentum, despite seasonal challenges in the first quarter.