Costco Wholesale (COST) Held by Superinvestors
COSTCO WHOLESALE CORP (COST) is currently held by 10 superinvestors tracked by InsiderSet, with a combined reported market value of approximately $895.97M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Parnassus Endeavor Fund is currently the largest disclosed institutional shareholder of COST tracked by InsiderSet, reporting ownership valued at approximately $584.72M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $584.85M, representing an estimated gain of +0.02% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed COST value among the investors covered in this analysis. Major shareholders include Parnassus Endeavor Fund, Greenbrier Partners Capital Management, Sequoia Financial Advisors, and several other long-term asset managers with concentrated positions in COSTCO WHOLESALE CORP (COST).
This page ranks the largest institutional COST shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Parnassus Endeavor Fund | Parnassus Investments | 1.56% | 625,050 | $584,715,524 | $584,846,784 | +$131,260 | +0.02% |
| Greenbrier Partners Capital Management | Frederick (Shad) Rowe | 15.54% | 221,730 | $207,421,763 | $207,468,326 | +$46,563 | +0.02% |
| Sequoia Financial Advisors | 0.44% | 94,833 | $88,713,855 | $88,733,341 | +$19,486 | +0.02% | |
| Alapocas Investment Partners | David Lemons | 4.57% | 5,000 | $4,677,350 | $4,678,400 | +$1,050 | +0.02% |
| Gardner Russo & Quinn | Thomas Russo | 0.04% | 3,399 | $3,179,709 | $3,180,376 | +$667 | +0.02% |
| Semper Augustus Investments Group | Christopher Bloomstran | 0.35% | 3,354 | $3,137,566 | $3,138,271 | +$705 | +0.02% |
| Mairs & Power Growth Fund | Andrew R. Adams | 0.03% | 2,963 | $2,771,798 | $2,772,420 | +$622 | +0.02% |
| Torray Fund | Robert Torray | 0.08% | 628 | $587,475 | $587,607 | +$132 | +0.02% |
| Matrix Advisors Value Fund | David Katz | 0.04% | 551 | $515,137 | $515,560 | +$423 | +0.08% |
| Cullen Value Fund | Jim Cullen | 0.03% | 263 | $246,216 | $246,084 | -$132 | -0.05% |
Frequently asked questions about COST
Who are the largest superinvestors holding COST?
The largest superinvestors holding COST in the latest SEC Form 13F filings include Parnassus Endeavor Fund, Greenbrier Partners Capital Management, Sequoia Financial Advisors, Alapocas Investment Partners, and Gardner Russo & Quinn. InsiderSet ranks these superinvestors by their latest reported COST position.
What does the COST superinvestors page include?
This page tracks COST positions reported by a curated group of notable institutional investors and fund managers through SEC Form 13F. COSTCO WHOLESALE CORP (COST) on this page reflects disclosed 13F holdings among those superinvestors, not every institutional shareholder of the stock.
How many superinvestors hold COST?
InsiderSet currently tracks 10 superinvestors reporting COST holdings in the latest available 13F data. This is the curated set on this page, not the total number of institutions that own COST.
How much COST stock do superinvestors hold?
Superinvestors tracked by InsiderSet disclosed approximately $895.97M in COST holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value, and it covers the curated superinvestors on this page rather than every institutional filer.
When were COST superinvestor holdings last updated?
The latest COST superinvestor holdings on InsiderSet are based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time holdings.
Are superinvestor COST holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by these superinvestors as of the end of the reporting quarter. A superinvestor may have changed its COST position after the reporting date.
Are superinvestors buying or selling COST?
Buying and selling can be analyzed by comparing COST positions across consecutive 13F reporting periods. InsiderSet's COST Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View COST ownership changes.
How have superinvestor COST holdings changed over time?
InsiderSet tracks COST holdings among these superinvestors across multiple 13F reporting periods, so holder counts, reported value, and reported shares can be compared over time.