Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) experienced a significant after-hours plunge of 5.32% following the release of its fourth-quarter and full-year 2025 financial results.

The biopharmaceutical company reported a quarterly net loss of $1.29 per share, which was wider than the $1.09 loss per share anticipated by analysts polled by FactSet. While revenue of $207 million for the quarter surpassed expectations, the company's forward-looking guidance disappointed investors.

For 2026, Ultragenyx issued revenue guidance for its current products in the range of $730 million to $760 million, falling short of the analyst consensus estimate of $791.3 million. Concurrently, the company announced a strategic restructuring plan, including a 10% reduction of its workforce affecting approximately 130 employees, as it aims to chart a path to profitability by 2027.