IDEXX LABORATORIES INC (IDXX) Institutional Ownership Changes & 13F Activity

IDEXX LABORATORIES INC (IDXX) institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC 13F filings (Q1 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions among tracked filers. Notable filers include Fundsmith, Polen Capital Management, Fundsmith Investment Services, Renaissance Technologies LLC, and Parnassus Endeavor Fund.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q3 2019Mairs & Power Growth FundSell-43,394$923
Q2 2019Renaissance Technologies LLCSell-196,100893,025$245,877
Q2 2019FundsmithBuy2,6974,470,038$1,230,736
Q2 2019Torray FundBuy751,350$372
Q1 2019Renaissance Technologies LLCSell-427,2041,089,125$243,528
Q1 2019FundsmithBuy85,2934,467,341$998,897
Q1 2019Sequoia FundSell-4461,146$256
Q4 2018Renaissance Technologies LLCSell-261,6751,516,329$282,068
Q4 2018FundsmithSell-44,5954,382,048$1,094,022
Q4 2018Mairs & Power Growth FundSell-9003,398$632
Q3 2018Renaissance Technologies LLCSell-310,9001,778,004$443,896
Q3 2018FundsmithSell-2,4614,426,643$1,105,156
Q3 2018Sequoia FundSell-1971,592$397
Q3 2018Torray FundBuy751,275$318
Q2 2018FundsmithBuy1,4474,429,104$965,278
Q2 2018Sequoia FundBuy4461,789$390
Q1 2018Renaissance Technologies LLCBuy209,1002,088,904$399,795
Q1 2018FundsmithBuy22,9014,427,657$847,410
Q1 2018Sequoia FundBuy1,3431,343$254
Q1 2018Torray FundBuy1,2001,200$230
Q4 2017Renaissance Technologies LLCBuy290,0041,879,804$293,964
Q4 2017FundsmithSell-39,9524,404,756$688,816
Q4 2017Mairs & Power Growth FundSell-3004,298$672
Q3 2017FundsmithSell-9,603,5024,444,708$686,218
Q3 2017FundsmithBuy9,602,17014,048,210$897,962
Q3 2017Renaissance Technologies LLCBuy237,9001,589,800$247,198
Q2 2017Renaissance Technologies LLCBuy376,3001,351,900$218,224
Q2 2017FundsmithSell-34,1674,446,040$717,680
Q1 2017Renaissance Technologies LLCBuy362,400975,600$150,838
Q1 2017FundsmithBuy3,3414,480,207$692,685

Frequently asked questions about IDXX activity

  • Which institutional owners are buying IDXX?

    Institutional owners buying IDXX include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in IDXX activity?

    "Buy" means an investor increased their reported position in IDXX compared to the prior reporting period. This reflects growing exposure to IDEXX LABORATORIES INC (IDXX) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in IDXX increasing?

    Institutional interest in IDXX can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.

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