Investor Slashes $70 Million From Zymeworks as Stock Jumps 60% in a Year

Redmile Group disclosed a significant reduction in its Zymeworks (ZYME 2.57%) position in a February 17, 2026, SEC filing, selling an estimated $70.10 million in shares based on quarterly average pricing.

What happened

According to a February 17, 2026, SEC filing, Redmile Group reduced its stake in Zymeworks by 3,214,096 shares, with the estimated transaction value totaling $70.10 million based on the average closing price during the fourth quarter of 2025. The quarter-end value of the position decreased by $50.35 million, a result of both share sales and stock price movements.

What else to know

• Post-sale, Zymeworks accounts for 0.95% of Redmile’s reportable 13F AUM.
• Top holdings after the filing:
  • NASDAQ:SRRK: $229.98 million (16.9% of AUM)
  • NASDAQ:KRYS: $167.08 million (12.3% of AUM)
  • NASDAQ:NRIX: $153.54 million (11.3% of AUM)
  • NASDAQ:STOK: $128.04 million (9.4% of AUM)
  • NASDAQ:IMNM: $122.83 million (9.0% of AUM)
• As of February 17, 2026, shares of Zymeworks were priced at $23.07, up roughly 60% over the past year and outperforming the S&P 500’s roughly 13% gain in the same period.

Company overview

Company snapshot

• Zymeworks develops and commercializes biotherapeutics for cancer, with lead candidates including zanidatamab (a bispecific antibody in Phase 1/2 trials) and ZW49 (an antibody-drug conjugate in Phase 1 trials).
• The firm operates a clinical-stage biopharmaceutical model, generating revenue primarily through licensing agreements, research collaborations, and milestone payments from strategic partners.
• It targets pharmaceutical companies and healthcare providers focused on oncology, addressing unmet medical needs in cancer treatment.

Zymeworks is a clinical-stage biotechnology company specializing in the discovery and development of innovative cancer therapies, leveraging a robust pipeline and strategic partnerships with major pharmaceutical firms. The company’s focus on bispecific antibodies and antibody-drug conjugates positions it at the forefront of targeted oncology therapeutics. Zymeworks’ collaborative business model and proprietary technology platforms provide a competitive edge in advancing next-generation cancer treatments.

What this transaction means for investors

When a top biotech holder cuts a position to under 1% of assets after a sharp rally, that shift is worth noting, particularly since Zymeworks entered 2026 with tangible momentum. Positive Phase 3 HERIZON-GEA-01 data for zanidatamab in first-line HER2-positive gastroesophageal cancer showed a statistically significant progression-free survival benefit and a median overall survival exceeding two years in combination therapy. The company is eligible for up to $440 million in regulatory milestone payments tied to approvals in major markets. It also ended 2025 with approximately $270.6 million in cash and marketable securities, and has a $125 million share repurchase authorization in place.

Against that backdrop, trimming into strength looks more like capital recycling than a loss of faith. This fund still runs a concentrated biotech portfolio, with double-digit allocations to other clinical names.

Shares are up roughly 60% over the past year, far outpacing the broader market. Ultimately, however, Zymeworks now sits in a transition phase, balancing royalty aggregation, internal R&D, and capital returns, and position sizing reflects that evolving risk profile.