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

This clinical-stage biotech develops targeted cancer therapies, leveraging bispecific antibodies and strategic industry partnerships.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 happenedAccording 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 knowPost-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 overviewMetricValuePrice (as of market close 2026-02-17)$23.07Market Capitalization$1.74 billionRevenue (TTM)$134.48 millionNet Income (TTM)($63.43 million)Company snapshotZymeworks 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 investorsWhen 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.About the AuthorJonathan Ponciano is a contributing stock market analyst at The Motley Fool. He has nearly a decade of experience as a financial journalist, most recently as an editor and senior reporter at Forbes focused on markets, technology, and entrepreneurship. Jonathan has also written for Investopedia and the Los Angeles Business Journal. He holds a dual B.A. in Business Journalism and Economics from the University of North Carolina at Chapel Hill and an M.B.A. from Columbia Business School. A North Carolina native now based in New York City, Jonathan has also lived in Mexico City and Los Angeles.CMFjonponcStocks MentionedZymeworksNASDAQ: ZYME$22.72 (2.57%) $0.60*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.