Baron Partners Fund is Leveraging IDEXX Laboratories’ (IDXX) Long-Term Growth Drivers

Baron Fund, an investment management company, released its Q4 2025 letter for “Baron Partners Fund”. A copy of the letter can be downloaded here. The Fund increased considerably in the fourth quarter, returning 19.07% (Institutional Shares). It outperformed both the Russell Midcap Growth Index (the Benchmark), which returned -3.70%, and the broader Russell 3000 Index, which returned 2.40% in the quarter. The Fund returned 24.86% in the calendar year, significantly outperforming the Russell Midcap Growth Index, which posted a return of 8.66%, and the Russell 3000 Index, which returned 17.15%. The Fund focuses on long-term investments in a non-diversified portfolio of well-managed growth businesses at attractive prices across market caps. It has consistently delivered strong absolute and relative performance over the long term. The Fund has seen substantial appreciation during good times and has preserved value during challenging periods. 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 Partners Fund highlighted stocks like IDEXX Laboratories, Inc. (NASDAQ:IDXX). IDEXX Laboratories, Inc. (NASDAQ:IDXX) is a US-based healthcare company that manufactures products for the companion animal veterinary, livestock and poultry, dairy, and water testing industries. On February 10, 2026, IDEXX Laboratories, Inc. (NASDAQ:IDXX) stock closed at $646.53 per share. IDEXX Laboratories, Inc. (NASDAQ:IDXX) delivered a -9.00% return in the past month, and its shares are up 41.36% over the past twelve months. IDEXX Laboratories, Inc. (NASDAQ:IDXX) has a market capitalization of $51.73 billion.

Baron Partners Fund stated the following regarding IDEXX Laboratories, Inc. (NASDAQ:IDXX) in its fourth quarter 2025 investor letter:

“Veterinary diagnostics leader IDEXX Laboratories, Inc. (NASDAQ:IDXX) spent years developing new tests. One was released in 2025, and another is expected to come to market in 2026. Utilization of new tests has exceeded expectations. The company contributed to performance after again reporting better-than-expected financial results. We believe IDEXX’s competitive trends are outstanding, and we expect new proprietary innovations, such as InVue, MultiCue, and CancerDX to be meaningful contributors to growth in the years ahead. We also see increasing evidence that long-term secular trends around pet ownership and pet care spending have structurally accelerated, which should help support IDEXX’s long term growth rate. The stock appreciated 63.6% in 2025.”

IDEXX Laboratories, Inc. (NASDAQ:IDXX) is not on our list of 30 Most Popular Stocks Among Hedge Funds. According to our database, 55 hedge fund portfolios held IDEXX Laboratories, Inc. (NASDAQ:IDXX) at the end of the third quarter, up from 48 in the previous quarter.  While we acknowledge the potential of IDEXX Laboratories, Inc. (NASDAQ:IDXX) as an investment, we believe certain AI stocks offer greater upside potential and carry less downside risk. If you’re looking for an extremely undervalued AI stock that also stands to benefit significantly from Trump-era tariffs and the onshoring trend, see our free report on the best short-term AI stock.

In another article, we covered IDEXX Laboratories, Inc. (NASDAQ:IDXX) and shared a list of best healthcare stocks to buy for 2026. 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.