Zymeworks (NYSE: ZYME) came into focus in late December when major shareholder EcoR1 Capital increased its stake. Already a 10% holder and board member, EcoR1 made several purchases in December and the first days of 2025, bringing its holding to over 15 million shares. This is a significant increase and affirmation of the outlook, including numerous catalysts in 2025. Among them are the recent approval of its flagship oncology treatment, the expectation for additional approvals, and the advancement of a robust and promising pipeline. What is Zymeworks? It is a clinical-stage biopharma working on novel treatments for hard-to-treat cancers and other diseases.
Actual insiders, the company’s executives, own a small fraction of the company, but a robust sell-side ownership offsets that. Institutions, including large shareholders like EcoR1 Capital, own more than 90% of the shares and aren’t selling. Regarding EcoR1, it is a boutique investment firm focused on novel therapies across a wide range of diseases.
