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
Q1 2021Durable Capital PartnersSell-76,996122,950$60,161
Q1 2021FundsmithSell-5,8164,220,612$2,065,188
Q1 2021Torray FundSell-1,28411,118$5,440
Q1 2021Sequoia Financial AdvisorsBuy25712$348
Q4 2020Durable Capital PartnersSell-183,112199,946$99,947
Q4 2020FundsmithSell-6,3874,226,428$2,112,665
Q4 2020Torray FundSell-59512,402$6,199
Q4 2020Mairs & Power Growth FundSell-133,404$1,702
Q4 2020Sequoia Financial AdvisorsBuy5687$343
Q3 2020Renaissance Technologies LLCSell-115,97687,204$34,281
Q3 2020Durable Capital PartnersSell-72,776383,058$150,584
Q3 2020FundsmithSell-7,8964,232,815$1,663,962
Q3 2020Parnassus Endeavor FundSell-1,63371,268$28,016
Q3 2020Sequoia Financial AdvisorsBuy682682$268
Q3 2020Torray FundSell-1312,997$5,109
Q3 2020Mairs & Power Growth FundSell-33,417$1,343
Q2 2020Durable Capital PartnersBuy228,294455,834$150,498
Q2 2020Renaissance Technologies LLCSell-147,945203,180$67,082
Q2 2020FundsmithSell-4,5164,240,711$1,400,113
Q2 2020Torray FundBuy1,08413,010$4,295
Q1 2020FundsmithSell-346,6724,245,227$1,028,364
Q1 2020Renaissance Technologies LLCSell-288,804351,125$85,057
Q1 2020Durable Capital PartnersBuy227,540227,540$55,119
Q1 2020Parnassus Endeavor FundBuy72,90172,901$17,660
Q1 2020Torray FundBuy10,57611,926$2,889
Q4 2019FundsmithBuy35,8834,591,899$1,199,083
Q4 2019Renaissance Technologies LLCBuy12,804639,929$167,105
Q4 2019Mairs & Power Growth FundBuy263,420$893
Q3 2019Renaissance Technologies LLCSell-265,900627,125$170,534
Q3 2019FundsmithBuy85,9784,556,016$1,238,917

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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