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
Q2 2018Mairs & Power Growth FundBuy2003,672$767
Q2 2018Ariel Appreciation FundBuy3,157229,982$48,062
Q2 2018Parnassus Endeavor FundSell-60,000290,000$60,604
Q2 2018Sequoia Financial AdvisorsSell-3661,617$338
Q2 2018Semper Augustus Investments GroupSell-3519,816$4,141
Q2 2018Sequoia FundSell-9620,709$4,328
Q2 2018Greenbrier Partners Capital ManagementBuy25,000250,000$52,245
Q1 2018Mairs & Power Growth FundBuy5963,472$654
Q1 2018Ariel Appreciation FundSell-7,688226,825$42,741
Q1 2018Gardner Russo & QuinnBuy5,4735,473$1,031
Q1 2018Sequoia Financial AdvisorsBuy1,9831,983$374
Q1 2018Semper Augustus Investments GroupSell-40019,851$3,741
Q1 2018Sequoia FundBuy20,80520,805$3,820
Q1 2018Renaissance Technologies LLCSell-1,122,013978,900$184,454
Q4 2017Mairs & Power Growth FundSell-1262,876$535
Q4 2017Ariel Appreciation FundBuy5,916234,513$43,648
Q4 2017Renaissance Technologies LLCBuy890,2002,100,913$391,022
Q3 2017Mairs & Power Growth FundSell-543,002$493
Q3 2017Ariel Appreciation FundBuy9,034228,597$37,556
Q3 2017Parnassus Endeavor FundBuy350,000350,000$57,502
Q3 2017Renaissance Technologies LLCSell-383,7871,210,713$198,908
Q2 2017Mairs & Power Growth FundSell-463,056$489
Q2 2017Ariel Appreciation FundBuy45,082219,563$35,115
Q2 2017Renaissance Technologies LLCSell-297,3001,594,500$255,008
Q1 2017Mairs & Power Growth FundSell-1633,102$520
Q1 2017Ariel Appreciation FundBuy7,613174,481$29,259
Q1 2017Renaissance Technologies LLCSell-927,9131,891,800$317,236
Q4 2016Mairs & Power Growth FundBuy263,265$523
Q4 2016Ariel Appreciation FundBuy91,201166,868$26,717
Q4 2016Semper Augustus Investments GroupSell-5120,251$3,242

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.