Rare Disease Stocks Plummet as Earnings Guidance Downgraded, 800 Billion Won Lost in Market Cap

Shares of BioMarin Pharmaceutical (NASDAQ: BMRN) closed at $54 on the Nasdaq, down 5.74%. About 2.2 million shares traded hands during the session, and the company’s market capitalization fell to roughly $10.5 billion (approximately KRW 15.7 trillion), wiping out about $570 million (around KRW 850 billion) in value.

In its first-quarter results, BioMarin reported revenue of $766.2 million (about KRW 1.1 trillion), a slight year-over-year increase. However, net income and earnings per share declined sharply. Citing integration costs and higher interest expenses from the Amicus acquisition, the company lowered its 2026 non-GAAP EPS guidance to $4.85–$5.05. This prompted some analysts to cut their price targets, adding further pressure on the stock.

On the other hand, reflecting the Amicus acquisition, BioMarin raised its full-year revenue guidance to $3.8–$3.9 billion (roughly KRW 5.7–5.9 trillion). Analysts believe the company’s mid- to long-term growth outlook remains intact, driven by an expanded rare-disease portfolio—including Galafold, Pomplity and Opfolda.

Headquartered in California, BioMarin Pharmaceutical is a biotech firm specializing in rare genetic disorders. Its product lineup includes vosoritide for bone-growth disorders and several enzyme-replacement therapies for other rare diseases.

Recently, the company acquired Inozyme and Amicus to broaden its pipeline, while withdrawing its hemophilia gene therapy Roctavian from the market. This “structural overhaul” is reallocating capital and R&D toward higher-margin rare-disease assets.