Baron Funds, an investment management company, released its fourth-quarter investor letter for the “Baron Health Care Fund”. A copy of the letter can be downloaded here. The fund rose 13.10% (Institutional Shares) in the quarter, compared to a 11.92% gain for the Russell 3000 Health Care Index (benchmark) and a 2.40% gain for the Russell 3000 Index (the Index). The Fund returned 10.28% for the full year, compared to 14.56% and 17.15% gains for the indexes, respectively. Strong stock selection in biotechnology contributed to the Fund’s relative gains in the quarter. The Fund seeks to invest in businesses with secular growth opportunities, a sustainable competitive edge, and strong management. The firm believes that healthcare is a strong sector in the U.S. economy, offering attractive investment opportunities with positive momentum heading into 2026. Please review the Fund’s top five holdings to gain insights into their key selections for 2025.
In its fourth-quarter 2025 investor letter, Baron Health Care Fund highlighted Repligen Corporation (NASDAQ:RGEN) as a new addition to the portfolio. Repligen Corporation (NASDAQ:RGEN) is a life science company that develops and distributes bioprocessing technologies and systems. The one-month return of Repligen Corporation (NASDAQ:RGEN) was -16.28%, and its shares lost 10.50% of their value over the last 52 weeks. On February 5, 2026, Repligen Corporation (NASDAQ:RGEN) stock closed at $139.66 per share, with a market capitalization of $7.862 billion.
Baron Health Care Fundstated the following regarding Repligen Corporation (NASDAQ:RGEN) in its fourth quarter 2025 investor letter:
“We bought shares of Repligen Corporation (NASDAQ:RGEN), a life science tools supplier to the bioprocessing industry. The company offers a broad portfolio of tools involved in the production of biologic drugs. We believe Repligen operates in attractive end markets, historically targeting monoclonal antibodies (8% to 10% market growth) and moving into cell and gene therapies (over 30% market growth). Repligen has a strong track record of smart acquisitions and innovation, including the introduction of differentiated filters and development of in-line process analytics (real-time monitoring of the drug production process). Because drug production is a highly regulated industry, bioprocessing suppliers are embedded into workflows and their products have high stickiness. Repligen did not have a mature portfolio when the original biologics came to market, so those original biologics tended to be on legacy competitor platforms—now, with generic versions (biosimilars) coming to market, Repligen has a unique opportunity to become embedded into new drug manufacturing processes with their differentiated systems. We see the opportunity for Repligen to drive an attractive, recurring consumables stream in an increasing number of commercial processes. We also believe Repligen is one of the select life science tools companies that can leverage AI. Biologic drug production is still quite manual today, and Repligen is leading the charge on incorporating systems that have real-time data collection. This gives Repligen a unique position to build up a data moat over the next 5-plus years, which we believe can help generate insights that make drug production more efficient. Finally, the recent announcements from large pharmaceuticals on reshoring should open up a significant capital equipment opportunity for players like Repligen. We think Repligen can double its revenue base in five years while expanding EBITDA margins by 1000 bps.”
Repligen Corporation (NASDAQ:RGEN) is not on our list of 30 Most Popular Stocks Among Hedge Funds. As per our database, 53 hedge fund portfolios held Repligen Corporation (NASDAQ:RGEN) at the end of the third quarter, which was 49 in the previous quarter. While we acknowledge the risk and potential of Repligen Corporation (NASDAQ:RGEN) as an investment, our conviction lies in the belief that some AI stocks hold greater promise for delivering higher returns and doing so within a shorter time frame. If you are looking for an AI stock that is more promising than Repligen Corporation (NASDAQ:RGEN) and that has 10,000% upside potential, check out our report about this cheapest AI stock.
In another article, we covered Repligen Corporation (NASDAQ:RGEN) and shared a list of best mid-cap growth stocks to buy. In addition, please check out our hedge fund investor letters Q4 2025 page for more investor letters from hedge funds and other leading investors.
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Disclosure: None. This article is originally published at Insider Monkey.
