COSTCO WHOLESALE CORP (COST) Stock Institutional Trading Activity


COSTCO WHOLESALE CORP (COST) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Renaissance Technologies LLC, Mairs & Power Growth Fund, Semper Augustus Investments Group, Matrix Advisors Value Fund, and Parnassus Endeavor Fund. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q4 2020Semper Augustus Investments GroupSell-10,4786,760$2,547
Q3 2020Parnassus Endeavor FundSell-201,2672,027,368$719,716
Q3 2020Gardner Russo & QuinnSell-265,393$1,914
Q3 2020Sequoia Financial AdvisorsBuy2,2592,259$802
Q3 2020Mairs & Power Growth FundSell-1413,352$1,190
Q3 2020Semper Augustus Investments GroupSell-1,92317,238$6,119
Q3 2020Renaissance Technologies LLCSell-890,079160,367$56,930
Q2 2020Lountzis Asset ManagementBuy5050$15
Q2 2020Parnassus Endeavor FundBuy3,5422,228,635$675,744
Q2 2020Gardner Russo & QuinnBuy3905,419$1,643
Q2 2020Sequoia Financial AdvisorsSell-2,7130$576
Q2 2020Semper Augustus Investments GroupSell-15519,161$5,810
Q2 2020Renaissance Technologies LLCSell-224,7721,050,446$318,506
Q1 2020Ariel Appreciation FundSell-31,85113,061$3,724
Q1 2020Parnassus Endeavor FundSell-53,2602,225,093$634,441
Q1 2020Gardner Russo & QuinnSell-1365,029$1,434
Q1 2020Sequoia Financial AdvisorsSell-172,713$773
Q1 2020Semper Augustus Investments GroupSell-319,316$5,508
Q1 2020Renaissance Technologies LLCBuy989,2051,275,218$363,603
Q4 2019Mairs & Power Growth FundBuy403,493$1,027
Q4 2019Ariel Appreciation FundBuy33444,912$13,201
Q4 2019Parnassus Endeavor FundBuy33,5412,278,353$669,653
Q4 2019Gardner Russo & QuinnSell-55,165$1,518
Q4 2019Sequoia Financial AdvisorsBuy3512,730$802
Q4 2019Semper Augustus Investments GroupSell-30019,319$5,678
Q4 2019Greenbrier Partners Capital ManagementSell-5,900242,632$71,314
Q4 2019Renaissance Technologies LLCSell-176,900286,013$84,065
Q3 2019Mairs & Power Growth FundBuy313,453$995
Q3 2019Ariel Appreciation FundSell-48,05744,578$12,843
Q3 2019Parnassus Endeavor FundBuy5,0312,244,812$646,753

Frequently asked questions about COST activity

  • Which institutional owners are buying COST?

    Institutional owners buying COST 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 COST activity?

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

  • Is institutional interest in COST increasing?

    Institutional interest in COST 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.