Cogent Biosciences Stock Soars 346% in a Year, but One Fund Just Sold Off $4.5 Million

On February 17, 2026, Rock Springs Capital Management disclosed in a U.S. Securities and Exchange Commission (SEC) filing that it sold 159,278 shares of Cogent Biosciences (NASDAQ:COGT), an estimated $4.48 million trade based on quarterly average pricing.

What happened

According to its SEC filing dated February 17, 2026, Rock Springs Capital Management LP reduced its stake in Cogent Biosciences by 159,278 shares during the fourth quarter. The estimated transaction value was $4.48 million, calculated from the period’s average unadjusted closing price. The quarter-end position value increased by $15.68 million, a figure that reflects both share count changes and market price appreciation.

What else to know

• This was a reduction; the post-trade stake accounts for 1.5% of reportable 13F assets under management.
• Top holdings after the filing:
  • NYSE: LLY: $113.27 million (5.8% of AUM)
  • NASDAQ: RVMD: $106.35 million (5.5% of AUM)
  • NASDAQ: ARGX: $86.83 million (4.5% of AUM)
  • NASDAQ: TVTX: $84.46 million (4.3% of AUM)
  • NASDAQ: MDGL: $81.31 million (4.2% of AUM)
• As of February 16, 2026, Cogent shares were priced at $36.53, up 346.6% over the past year and well outperforming the S&P 500 by 334.8 percentage points.

Company overview

Company snapshot

• Cogent Biosciences develops precision therapies targeting genetically defined diseases, with a lead product candidate (CGT9486) focused on inhibiting KIT mutations in systemic mastocytosis and gastrointestinal stromal tumors.
• The company operates a biotechnology business model, generating value through research, development, and potential commercialization of proprietary therapeutics, supported by strategic licensing agreements.
• It targets healthcare providers, clinical researchers, and patients affected by rare genetic disorders, particularly those with unmet medical needs in oncology and hematology.

Cogent Biosciences, Inc. is a biotechnology company specializing in precision therapies for genetically driven diseases, with a primary focus on rare oncology indications. The company's strategy centers on advancing selective tyrosine kinase inhibitors, leveraging proprietary research and strategic partnerships to address critical gaps in treatment. Cogent's competitive edge lies in its targeted approach to drug development for underserved patient populations.

What this transaction means for investors

When a biotech rallies more than 300% in a year, portfolio managers are forced to make a decision: press the bet or rebalance. That context matters here. Even after the fourth quarter trim, the position still represents 1.5% of reportable assets, suggesting conviction remains intact.

Cogent entered 2026 with serious momentum. The company submitted its NDA for bezuclastinib in NonAdvSM in December, initiated its PEAK NDA under the FDA’s Real-Time Oncology Review program for second-line GIST, and expects to submit its APEX NDA in AdvSM in the first half of 2026. Phase 3 PEAK data showed a median progression-free survival of 16.5 months versus 9.2 months for sunitinib alone, and a 46% objective response rate versus 26%. Meanwhile, cash and marketable securities totaled roughly $901 million at year-end, providing runway into 2028.

Within a portfolio dominated by large-cap biotech leaders like Eli Lilly and argenx, this remains a smaller, catalyst-driven name, but for long-term investors, the key question is not the trim. It is whether bezuclastinib can convert regulatory momentum into durable commercial execution in the second half of 2026 and beyond.

Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Argenx Se. The Motley Fool has a disclosure policy.