COSTCO WHOLESALE CORP (COST) Institutional Ownership Changes & 13F Activity

COSTCO WHOLESALE CORP (COST) 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 Renaissance Technologies LLC, Parnassus Endeavor Fund, Sequoia Financial Advisors, Greenbrier Partners Capital Management, and Alapocas Investment Partners.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q3 2017Parnassus Endeavor FundBuy350,000350,000$57,502
Q3 2017Ariel Appreciation FundBuy9,034228,597$37,556
Q3 2017Mairs & Power Growth FundSell-543,002$493
Q2 2017Renaissance Technologies LLCSell-297,3001,594,500$255,008
Q2 2017Ariel Appreciation FundBuy45,082219,563$35,115
Q2 2017Mairs & Power Growth FundSell-463,056$489
Q1 2017Renaissance Technologies LLCSell-927,9131,891,800$317,236
Q1 2017Ariel Appreciation FundBuy7,613174,481$29,259
Q1 2017Mairs & Power Growth FundSell-1633,102$520
Q4 2016Renaissance Technologies LLCBuy733,5002,819,713$451,464
Q4 2016Ariel Appreciation FundBuy91,201166,868$26,717
Q4 2016Semper Augustus Investments GroupSell-5120,251$3,242
Q4 2016Mairs & Power Growth FundBuy263,265$523
Q3 2016Renaissance Technologies LLCBuy1,748,5132,086,213$318,168
Q3 2016Ariel Appreciation FundBuy37,69775,667$11,540
Q3 2016Mairs & Power Growth FundBuy3413,239$494
Q2 2016Renaissance Technologies LLCSell-772,513337,700$53,032
Q2 2016Ariel Appreciation FundBuy23,13637,970$5,963
Q1 2016Renaissance Technologies LLCBuy514,2131,110,213$174,947
Q1 2016Ariel Appreciation FundBuy77114,834$2,338
Q4 2015Renaissance Technologies LLCSell-53,400596,000$96,254
Q4 2015Mairs & Power Growth FundSell-2402,898$468
Q3 2015Renaissance Technologies LLCSell-511,539649,400$93,884
Q3 2015Ariel Appreciation FundBuy10,35714,063$2,033
Q3 2015Mairs & Power Growth FundBuy3403,138$454
Q3 2015Semper Augustus Investments GroupSell-10020,302$2,935
Q2 2015Renaissance Technologies LLCSell-34,0611,160,939$156,796
Q2 2015Greenbrier Partners Capital ManagementBuy25,000225,000$30,389
Q2 2015Ariel Appreciation FundBuy2063,706$501
Q2 2015Mairs & Power Growth FundBuy1572,798$378

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.

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